Kaidou

Kaidou of the Beasts, renowned as the world's "Strongest Creature", is the Governor-General of the Beasts Pirates and one of the Four Emperors ruling over the New World. He is also the father of Yamato.

From his base on Onigashima, Kaidou has occupied Wano Country along with his crew and once allied with Wano's shogun, Kurozumi Orochi, until Kaidou decided to dispose of him for his New Onigashima Project. Decades ago, before the formation of his own crew, Kaidou was an apprentice in the legendary Rocks Pirates, where he ate the rare Mythical Zoan fruit, the Uo Uo no Mi, Model: Seiryu. He is currently in an alliance with his former Rocks crewmate and fellow Emperor, Big Mom.

Kaidou was first referred to by Monkey D. Garp in the Post-Enies Lobby Arc and then directly mentioned by Gecko Moria in the Thriller Bark Arc, with his status as one of the Four Emperors revealed after the Straw Hat Pirates defeated Moria. Thus, Kaidou is the third Emperor mentioned by name and the last to debut. Before he debuted in person, his voice was heard in a flashback that Kozuki Momonosuke had when first disembarking on Dressrosa.

He is the primary antagonist of the Wano Country Arc and one of the central antagonists of the Four Emperors Saga.

Appearance
Kaidou is a middle-aged man who cuts an imposing figure due to his extreme height of 710 cm and the bulk of his muscles, making him dwarf normal humans. Overly top-heavy in build, he has a well-muscled torso with wide-set shoulders, thick arms, and somewhat out-of-proportion legs; far less heavily built than his arms yet about the same length (with his feet much tinier than his hands). Kaidou's head, atop his bulky neck, is disproportionally small as well (smaller than his hands) and has a massive pair of gray-white, sharp-pointed horns come out of its sides, curving slightly to the front, then upward. He has a longish face with a heavy, hairless brow ridge topping sharp, often bloodshot eyes (parent to small, yellow irises), plus a hook nose and a large, full-lipped mouth. Kaidou is near-always seen frowning and is moderately wrinkled: particularly prominent being his crow's feet below his eyes, forehead lines, and laugh lines from always sneering. His black hair consists of an unruly, mostly swept-back mane down to his his mid-back, which forms distinctly flat, rectangular locks of which some fall down near the front, over his ears, or jut upward. His facial hair is done in a wavy, waist-length Fu Manchu mustache that pairs with a spiked goatee across his chin.

Right of Kaidou's defined abs is his only scar: a massive, recessed X-shape whose upper points reach to his pectoral, given to him by Kozuki Oden. Twenty years later, Roronoa Zoro managed to add another scar to Kaidou's chest that runs from the top left point of the first scar to near his left shoulder. A tattoo of dull-red segments resembling reptilian scales, individually bordered in orange, goes from Kaidou's left pectoral down the front of his left arm, ending in correspondence to the wrist with a white (dark in the manga), traditionally-shaped skull on the lower forearm.

Clothing-wise, Kaidou dons a blue-purple, feathered, sleeveless overcoat draped on his shoulders, and below a lavender, tight-fitting, open shirt with long sleeves. He has a black bracelet with golden (dark in the manga) spikes above each wrist. Upholding said shirt is a thick, off-white belt of laid rope festooned with a pair of white, hanging shide in the front. More outwardly from below the rope hang two additional pieces of fabric: rectangular, hemmed flaps (which may be the bottom of said shirt) that each have, from two hemmed holes at their bottom, a short, thick, golden torus chain attached to themselves. Two yellow straw cords are below the shimenawa, serving as waistbands to secure a short, hanging row of thin, red ribbons. Finally, the rest of his lower wear consists of simple, baggy pants of gray-green color, tucked below the knees into simple, black boots. After his battle against the Big Mom, Kaidou is seen wearing a white version of his usual shirt, which exposed the middle of his body.

20 years before the current storyline, Kaidou's Fu Manchu was only chest-length, he lacked his current beard, had much fewer wrinkles, and until his battle with Oden did not have any visible scars on him. While he was already very large and muscular back then, he was better proportioned compared to his current top-heavy build. When he was facing Gecko Moria, Kaidou wore a green-blue, open vest and black pants with a thick metal belt. During Oden's execution, he wore the pairing of a dark-blue, sleeveless leather jacket and dark-blue, tight leather pants, with a belt featuring his crew's Jolly Roger on its big, round, gold-framed buckle, in red color on a dark background, alongside black shoes. Additionally, he already wore his purple coat and spiked bracelets. At the time he was seen, due to the injury he suffered from fighting Oden, Kaidou's chest and abdomen were heavily bandaged up.

Personality
Kaidou is a merciless, aggressive, and confident warrior who never misses an opportunity to gain an advantage in war. He suffers from bouts of apathy and boredom, harboring a general sense of unconcern for most things including the very nature of the world and the lives of himself and his subordinates. He keeps a grumpy disposition with little pleasure and excitement in his life and is constantly frowning most of the time. As such, he craves excitement and chaos, wanting to start the largest war in the world because he felt it was too mundane. In the past, Kaidou believed that only he could change the world, supposedly in an attempt to mimic Joy Boy and his legend; however, Kaidou has admitted that his methods and overall goal ended up being far different. Still, Kaidou remains curious about Joy Boy and whether anyone else is capable of taking up their mantle.

It may not be the way of the times anymore... but death is what truly completes a person!

Kaidou's recklessness, coupled with his apparent inability to die from any execution method, has caused him to make attempted suicide as his hobby. Kaidou overall has a very positive view on death, thinking that it is the moment a person achieves true glory. As such, he admires those who die fighting until the very end, such as Gol D. Roger, Edward Newgate and Kozuki Oden and acknowledges the impact they end up causing in those moments. Kaidou becomes excited when battling enemies who can actually stand toe to toe with him in a fight, though he likewise feels immense disappointment when they fail to defeat him.



Kaidou is a heavy drunkard who loves to drink sake, which causes his mood to change erratically when he becomes inebriated. For example, he quickly went from being melancholic over his inability to increase the number of his Gifters and fulfill his dream of having a crew consisting of only Devil Fruit users to becoming angry and violent, brutally beating his subordinates and cursing Luffy and Law. While drunk, Kaidou may become more destructive by accident since he ends up caring little for his surroundings, to the detriment of his own crew and their operations. In fact, Kaidou is such a habitual drinker that he even dislikes being sober at any given time. His drunken mood swings have been exploited in battle as well through a special fighting style known as Shuron Hakke, which, by Kaidou's own admission, is only used on opponents that give him a challenge.

Kaidou is greatly annoyed at the number of people capable of Haoshoku Haki, stating that the world does not need so many people who could use it. Like several other characters, Kaidou has a unique laughing style: "Worororo" (ウォロロロ). A second one of his has been observed as he was drunk: "Fuhihihi" (フヒヒヒ).

Warmongering
With the goal of waging an all-out "final war" against the World Government, Kaidou ultimately seeks to form the strongest pirate crew consisting only of Devil Fruit users; so he actively seeks out formidable manpower in the New World to recruit into his growing army, including Super Rookies like Basil Hawkins, Scratchmen Apoo, and X Drake. Rather than kill those who resist him, he attempts to break their spirit through torture and forced labor until they either die or submit to his cause. Kaidou also has an interest in finding the Ancient Weapons and the One Piece for his cause; having taken a Road Poneglyph under his ownership and ruthlessly hunting down Kozuki Momonosuke as well as his three retainers, Kin'emon, Raizo, and Kanjuro, in the chance that Kozuki Oden may have imparted some knowledge to them.

Kaidou is pragmatic enough to avoid conflict that could devastate his forces and territories. When Big Mom attempted to invade Wano Country, Kaidou feared it would become an all-out war and furiously ordered his crew to stop her, especially after being aware that Big Mom's powerful children were accompanying their mother. This was true even in the past, when Oden returned to Wano Country from his journey. Kaidou agreed with Orochi to trick Oden into submission by making a fake deal with him, giving himself time to reinforce his army. Kaidou even admitted to being unsure of fighting Oden during the time of their first meeting, acknowledging the daimyo's infamous bold nature.

Savagery
Friendship is a sham! It's all for show! Deep down, they fear you! You must rule with strength! You are the child of ogres! You are not meant to be friends with humans!

Akin to the reputation of an oni, Kaidou is savage, brutal and believes that might makes right, using his near unrivaled power to govern others through fear and intimidation while making examples of them should they ever decide to not obey or rebel against his rule. Kaidou, interestingly, does not seem to view himself as a human at all, fiercely thinking that his lineage should not hold a friendly relationship with other humans, but rather distrust and oppose them, under the reasoning that the latter are unable to view the former as anything else than monsters.

Kaidou is extremely cruel, even towards children. After murdering Kozuki Oden, he viciously insulted Oden right in front of his son Momonosuke, adding mockery to Momonosuke's sorrow and hopelessness. Adding to this, he brutally attacked Tama and practically left her for dead. Kaidou also bluntly informed Queen about Komurasaki's "death" while casually laughing at Queen's despair over the death of his idol and later found amusement upon seeing Orochi's spiteful execution of Yasuie as well as his ally's cruelty in feeding his own citizens faulty SMILE fruits. As an abusive father, Kaidou has no qualms beating up his daughter Yamato since childhood, showing that even his own child is not spared from his violence and wrath.

Kaidou is known to be hard to reason with and not usually open for negotiations or excuses, making it unwise to provoke or underestimate him; this is enforced dramatically when Donquixote Doflamingo, a former Warlord of the Sea and former World Noble known for his fearless attitude, became disturbed at the prospect of angering Kaidou when he became potentially unable to fulfill his end of their business deal. One of his crewmates later stated that Kaidou would be very angry once he heard the news of the SMILE Factory's destruction, leading to a squad of them attempting to loudly deliver the information from a distance in order to avoid any potential retaliation. Despite this, Kaidou is not completely impossible to reason with, demonstrated by his capacity to form an alliance with another Emperor he had attempted to kill days prior.

Arrogance and Respect for Power
Kaidou is highly confident in his power and considers himself to be far above the likes of Super Rookies, to the point of even refusing to take the Straw Hat Pirates and Heart Pirates seriously despite them crippling his SMILE trade; this is reinforced by his belief that defeating a Warlord of the Sea is nothing to be impressed with and subsequent dismissal of Donquixote Doflamingo as being weak. He was quick to threaten to kill Big Mom when she announced her intention to come to his territory, showing no reservations against someone possessing power equivalent to his own. Kaidou seemingly enjoys to take direct attacks from enemies he perceives as strong in order to test their strength, doing so with much amusement.

Despite his immense arrogance, Kaidou does acknowledge other individuals of exceptional strength, such as Ashura Doji and Eustass Kid, wishing to have both become subordinates of his despite their constantly defiant attitude. This extends to Luffy, one of the people responsible for the halting of his SMILE trade that was vital to Kaidou's ultimate goals, yet the Emperor chose to have the Straw Hat captain imprisoned so he could be recruited as a soldier of formidable power instead of killing him. Due to his respect for power, Kaidou is willing to offer strong subordinates a chance to be promoted to an All-Star in his crew as long as they prove it in an authorized challenge against a current one. Since Kaidou sees and acknowledges an enemy's power, he does not blame his subordinates for losing battles against opponents that he deems appropriately powerful. Kaidou forgave Jack for losing to Nekomamushi and Inuarashi in their Sulong forms, because he understands that Jack is not weak, but rather that his enemies were merely too strong to handle.

Honor and Treachery
While Kaidou is vicious and ruthless to his enemies, he also utterly despises interferences in his struggles and will absolutely not forgive anyone who does so, showcasing a form of warrior's pride and honor. When he met Big Mom again for the first time in decades, he told his men to take her Seastone cuffs off before trying to kill her, strictly preferring to fight his enemies fair and square despite having an easier chance to kill his fellow Emperor in a weakened state. When a member of the Beasts Pirates seemingly captured Kozuki Momonosuke (in truth Kurozumi Higurashi in disguise) as a hostage to distract Oden, Kaidou only took the opportunity to strike Oden down because he did not know of the situation until afterwards. Intolerant of foul play in regards to his own battles, Kaidou killed Higurashi for interfering regardless of her being one of Orochi's closest supporters, and upon witnessing the Legendary Hour, Kaidou was solemnly impressed by Oden's strength and willpower. As a last sign of respect, he informed Oden about Higurashi's demise while apologizing for her meddling in their battle and opted to kill Oden himself with a gunshot.

Honorable moments aside, Kaidou can be rather treacherous and opportunistic. He seemingly believes that betrayal is part of a pirate's nature and admitted that he overlooked the threat of the Nine Red Scabbards because he never expected noble samurai to ally with pirates. Kaidou is not above making false promises, having lied to Oden twice to keep the daimyo and his country in check. The first time, it was to buy time as Oden demoralized himself to Wano's citizens for years, allowing Kaidou to build more strength for his army. The second time was to have Oden and the Scabbards killed so the country would lose their hope of revolution, despite a prior agreement to spare them if they survived a certain punishment. Kaidou also has no qualms killing allies should they outlive their usefulness, having beheaded Orochi once the latter questioned his plot to reform Wano into a pirate paradise despite their alliance of over two decades.

Crew
Kaidou is determined to build his crew into the strongest army of Devil Fruit users ready for what he has declared to be the biggest all-out war against the World Government. Thus, he actively sought out strong and formidable manpower in the New World to draft into his ranks, from pirates such as the Super Rookies from the Worst Generation to the leader of the Mt. Atama Thieves, Shutenmaru. Those who resist or defy his attempts are often sent to slave away at the mines of Udon until they either die or their spirits break and submit to Kaidou. As such, a great portion of the Beasts Pirates consists of former independent pirates who have given up their own goals in order to serve him.

Kaidou himself has not demonstrated much concern for the well-being of his crew, although he does seem to care about them to a degree, as Scotch stated that Kaidou would go after X Drake if the latter attacked him. Kaidou is invested in making his crew stronger by giving them artificial Zoan powers with SMILE and, under his permission, incentivizes battles between his own crewmembers so they can attain higher ranks in his organization. When Kaidou gets drunk and emotional, he can get very violent against his subordinates and may end up smashing them around with his kanabo, although if he is in a good enough mood, he might just ignore them. Still, Kaidou's men tend to become concerned in those cases anyway, since their captain is known for rampaging around indiscriminately and causing damage to their own territories and facilities.

King
Kaidou has known King for over three decades, with the two of them meeting as test subject prisoners on Punk Hazard before the Beasts Pirates were formed; it appears that their union marked the beginning of the crew's formation. Kaidou appeared to be interested in King due to his strength, and when told of his original name "Alber", suggested he adopt the name King as a reflection of his status and power.

King has been fiercely loyal to Kaidou ever since, believing in Kaidou's declaration that he was the only one who could change the world and declaring with great faith that Kaidou would become the next Pirate King. King also seemingly thought in the past that Kaidou could attain the identity of Joy Boy, but eventually stopped caring about any comparisons with the legend.

Queen
Upon delivering the news of Komurasaki's apparent death to Queen, Kaidou was unconcerned about Queen's feelings upon hearing this despite the All-Star being enamored with her, to the point of even mocking him for crying about it.

Jack
As one of his All-Stars, Kaidou cares about Jack's well-being a great deal. When he heard about Jack failing to rescue Doflamingo from the Marines, Kaidou was more concerned about the loss of his SMILE, though his lack of concern about Jack may have been due to Jack being a fish-man and therefore likely to survive naval combat. When Jack was brutally beaten by Inuarashi and Nekomamushi after the two minks activated their Sulong forms, Kaidou intervened to save Jack's life. He held no grudge against Jack for being defeated, knowing that it was due to the minks' extreme strength rather than the All-Star's weakness; in fact, he even commended Jack for his work in keeping the other minks at bay and told him to get his wounds treated.

Tobiroppo
The Tobiroppo consist of the six strongest Shinuchi in the Beasts Pirates. Kaidou appears to be very proud of them, wishing to introduce them to his fellow Emperor and ally Big Mom. He also trusts them with missions dealing with his daughter Yamato.

The Tobiroppo seem to have the utmost respect for their captain. Ulti is not afraid of criticizing Kaidou's familial issues, much to the shock of her companions, but otherwise genuinely thinks that her boss will eventually become pirate king, enough to become massively angered towards anyone who dares to dispute that claim. Sasaki shows interest in socializing solely with Kaidou, looking down on those in the lower ranks. Black Maria acts in a flirty way towards her captain and appears to enjoy his company.

Charlotte Linlin
Kaidou and his fellow Emperor Charlotte Linlin, better known as Big Mom, have been rivals with each other ever since they were crewmates on the Rocks Pirates, and both of them would like nothing more than to kill the other. Kaidou threatened to kill Big Mom if she entered his territory and tried to kill Luffy, whom he wanted for himself, and did not appear to care about Linlin claiming that he owed her a debt. Part of that debt is from her giving him the Uo Uo no Mi, Model: Seiryu after the God Valley Incident. However, Kaidou does not wish to kill Big Mom in an underhanded manner but wants to beat her in equal combat, as when she was captured and brought to Onigashima, he ordered his subordinates to release her from her Seastone chains before he fought her.

However, following their battle, Kaidou and Big Mom found common ground in their dream of taking over the world and they temporarily put aside their differences in order to achieve their goal. They now act quite jovially around each other as they drank together and were excited about working together again, although they ultimately still wish to kill each other once they achieve their dream.

Kaidou and Big Mom have a very vitriolic attitude towards each other while fighting side by side, trading insults and pointing out behaviors they perceive as annoying coming from the other, like Big Mom showing irritation at Kaidou's habit of taking attacks head-on to test the strength of his adversaries. That being said, they have great combat synergy and are considered unbeatable together, to the point that the Worst Generation pirates fighting them had to devise a plan to separate the two in order to stand a chance. Kaidou and Big Mom are also capable of performing a formidable combination technique, Hakai, that is capable of decimating everything in their way.

Donquixote Doflamingo
Kaidou and Doflamingo had a business partnership where Doflamingo supplied Kaidou with SMILE fruits in exchange for weapons, which he significantly invested in his goal to make his crew the strongest of Devil Fruit users. Word of Doflamingo's defeat and the destruction of the SMILE factory brought Kaidou mourning at his loss much to his drunken emotional sorrow. Law later states that Kaidou would have killed Doflamingo if he ceased producing SMILE, and Doflamingo became very fearful at the possibility of incurring Kaidou's wrath when Luffy and Law threatened his production. Despite calling him weak, Kaidou heavily valued Doflamingo's business to the degree that when Doflamingo was captured by the Marines, he ordered Jack to stop hunting for one of the Kozuki Family's retainers and to free Doflamingo from an armada of Marine warships escorting him to Impel Down.

Yamato


Yamato is Kaidou's daughter and only known blood-relative. The two of them have a strained relationship, as Yamato idolizes Kaidou's enemy, Kozuki Oden, a fact that drove multiple conflicts between the two. However, Yamato still emulated Oden for the past 20 years to the point of even presenting herself as a man like him, and although Kaidou disapproves of her idolizing him, he does refer to her as his "son". Kaidou does not seem to be aware that Yamato wishes to fulfill Oden's dream of opening Wano's borders, a cause to which he is opposed.

Kaidou: Orochi had a skill for exploitation. This country is a weapons factory! You will rule over it, and keep it running! Yamato: No, I will free them! I will liberate this country and its samurai... and release them unto the world! Kaidou: You will not! You will never!

Kaidou has been cruel to Yamato ever since her childhood. When Kaidou first learned of Yamato's desire to be like Oden, he imprisoned her inside a dark cave without any food and with other samurai that held a grudge against him, putting her in direct danger. It was this event that led Yamato to become Kaidou's enemy, intending to fight him in the promised time, according to Oden's logbook. Along the years, Kaidou beat Yamato numerous times, keeping her life in precarious conditions through explosive handcuffs, which prevented her from simply sneaking away by setting sail, and frequent hunger, driving Yamato to eat one of Kaidou's valuable Devil Fruits. Kaidou's overall view of Yamato is contradictory; he casually refers to her as an "idiot", but wished to have her participate in his party during the Fire Festival and later even replace Orochi as shogun, being confident that Yamato would eventually follow his will and protect Wano under his rule. When Kaidou finally confronted Yamato during the Onigashima Raid, he continuously mocked his daughter for attempting to rebel against him by allying with the enemy alliance, forcefully telling her to stay in Wano and become its guardian.

In return, Yamato seems to have a very low opinion of her father and has claimed to have attempted to defeat him multiple times in the past in order to attain freedom, being particularly frustrated about the explosive handcuffs that would detonate if she attempted to escape. She sought Monkey D. Luffy precisely to join forces with him in order to take down Kaidou and did not object to the idea of Luffy defeating him. Yamato was noticeably angry when Kaidou announced his plans to have her become the next shogun of Wano, which showed signs that she did not wish to be their father's pawn like Orochi was.

Once Yamato realized that Kaidou was willing to even kill his own daughter (after Luffy removed her handcuffs and they indeed exploded), she officially disowned him as her parent and did not even appear to care if he were to die during the raid on Onigashima, becoming intent on cutting any remaining ties they once had. This is reflected by Yamato, after being freed from her handcuffs, dropping the usage of "father" whenever addressing Kaidou, only referring to him by name instead.

Kozuki Family
Kaidou became mortal enemies with the Kozuki Family, as he worked with Orochi to kill Kozuki Oden and caused Kozuki Toki's death while attempting to kill her and her children, Momonosuke and Hiyori.

Kozuki Oden
As the first person to have ever injured him, Kozuki Oden left a deep, strong impression on Kaidou.

Kaidou thought highly of Oden, having heard of the samurai's infamous reputation prior to their actual meeting, to the point of prioritizing the gradual expansion of his army to properly tackle the Kuri daimyo. Impressed by the man's feat of surviving a boiling pot of oil for a whole hour, Kaidou decided to kill Oden himself as a sign of respect, acknowledging that his enemy had died as a legend.

In spite of Oden's death ever since, Kaidou still seems to be haunted by his fight with him, particularly the fact that he could have died that day if it were not for Higurashi's actions. When the Nine Red Scabbards ambushed him during the raid on Onigashima, he was shocked to see Oden's image in them, reminiscent of how he was nearly defeated by their master twenty years ago. When the Scabbards successfully injured him, the scar he received from Oden started hurting to the point he screamed in agony. Later on, after finally evaluating the Scabbards' strength during their fight at the top of the Skull Dome, Kaidou concluded that, in spite of carrying Oden's will, the Scabbards would never be able to measure to their fallen master, with the Emperor even claiming that it was an impossible task for any samurai.

Kozuki Momonosuke
In the past, Kaidou threatened to kill Momonosuke, holding him by the throat above the Kuri Castle when Momonosuke declared his ambition to be the shogun. Kaidou considered him an immature brat in response, knowing that Momonosuke was only speaking out of duty rather than actual ambition. Considering him as pathetic compared to his father, Kaidou chose to leave Momonosuke behind in the burning castle rather than kill him personally. This experience has ever since caused Momonosuke to be afraid of heights, refusing to fly despite that being within his capabilities while in dragon form.

Because of Kaidou's actions, Momonosuke and his retainers wish to bring him down after being sent 20 years forward in time by Toki and have spent all their time working to form an alliance to accomplish this. When Kaidou first saw Momonosuke again after twenty years, he remained unimpressed upon seeing him brutally beaten by Kanjuro. He also questioned Momonosuke whether he was truly Oden's son, claiming that he did not inherit any of his father's strength and guts, which he thought highly of. Repeating the question he asked twenty years ago, Kaidou offered to spare Momonosuke if he denied about his heritage. When Momonosuke refused to lie, Kaidou prepared to execute him as a Kozuki in order to officially start his New Onigashima Project. After Luffy's rematch with Kaidou which ended in the former's second loss, Kaidou personally hunted down Momonosuke, and brutally injured Kinemon his guardian, causing Momonosuke to cry profusely. When Momonosuke flew to Onigashima as an adult Dragon, Kaidou was surprised while also claiming only one Dragon is allowed to exist.

Nine Red Scabbards


To fulfill Oden's wish of opening Wano's borders, the Scabbards (except Kanjuro, who was a traitor) plotted to defeat Kaidou.

Ten years before Momonosuke's return, Ashura Doji gave up hope after his comrades became impatient and perished trying to fight the Beasts Pirates. Kaidou was impressed with Ashura's strength and wanted him to join his crew. Although he had stopped following the Kozuki Family, Ashura had no wish to serve Kaidou and refused, though Kaidou remained open to him joining and offered to forgive Ashura if he did. However, after Yasuie sacrificed himself to give the Kozuki revolution a chance, Ashura eventually rejoined the Kozuki Family and their quest to bring down Kaidou. Kaidou was shocked to learn that most of them survived and were in the future. He was surprised to hear Kanjuro, whom he had nearly killed twenty years ago, was in reality, a secret ally of Orochi and was very impressed by Kanjuro for his deceptive skill that had also fooled him. The remaining Scabbards, bearing twenty years of anger and hatred over their master's death, eventually succeeded in ambushing him during the Fire Festival. Kaidou was surprised to learn that Kyoshiro is actually Denjiro and Ashura Doji was a member as well. Despite proudly claiming that they could never hurt him, Kaidou envisioned Oden's angry image commanding he leave Wano and never return as they furiously attacked him, pushing him off his feet. When the Scabbards actually injured Kaidou and made him scream in pain, he went serious enough to take the battle outside of the Skull Dome with the Scabbards.

Edward Newgate
Much like with Big Mom, the late Whitebeard was Kaidou's fellow Emperor and former crewmate on the Rocks Pirates. While acknowledging and respecting him for his power, Kaidou viewed Whitebeard as too soft because of his morals and honor code. Prior to the Summit War of Marineford, Kaidou attempted to intercept Whitebeard while he was on his way to Marineford with the intention of killing him, although the attempt was stopped by Shanks. Two years later, he cursed Whitebeard for being able to die while he was unable to.

Shanks
Not much is known about the relationship between Kaidou and Shanks, but Kaidou does seem to acknowledge Shanks' abilities, considering him among the few powerful individuals capable of fighting him.

Worst Generation
As a member of the Four Emperors, Kaidou serves as an obstacle for the Worst Generation in their quest to obtain the One Piece.

Monkey D. Luffy
Kaidou first heard of Luffy after finding out that he worked with Trafalgar Law to destroy his SMILE production. He refused to consider Luffy a serious threat, viewing him defeating Donquixote Doflamingo as nothing special. However, he still held a grudge over Luffy for his actions in Dressrosa, swearing revenge on the Straw Hat captain for ruining his SMILE deal with the Warlord of the Sea and telling Big Mom that he would kill the boy himself for it.

When Kaidou heard about Luffy and Law's presence in Wano territory, he personally went to the Kuri region to demand that his subordinate Jack search for and capture them as fast as possible. Kaidou eventually fought Luffy shortly after and, although he defeated the Straw Hat captain in one hit, he was impressed by his fighting talent and ordered the boy's imprisonment, wishing to break the young pirate's spirit and have him as a soldier within his crew.



During the raid on Onigashima, once they finally fought again, Kaidou was shocked that Luffy had managed to learn a method to penetrate his defenses, mentally comparing him to other big names of pirate history: Roger, Whitebeard, Oden, Shanks, and his former captain, Rocks. Kaidou was also impressed that Luffy was not going down as easily as in their first encounter, praising the young pirate for properly defending himself against some of his stronger attacks. Kaidou overall grew more and more amused with Luffy's spirit, thrill for battle, and quick growth the more they fought, seemingly acknowledging the Straw Hat captain as a worthy opponent akin to Oden. This is further evidenced by the fact that Kaidou regretted not having killed Luffy in a more definitive way once the latter was knocked off of Onigashima, as not doing so meant he would be unable to truly crush the spirits of everyone that had deposited their faith into Luffy's survival and victory.

Luffy views Kaidou as one of his biggest obstacles in the way of his goal of becoming the Pirate King, having stated several times that he wished to bring him down as well as the other Four Emperors. In Wano, Luffy learned from Kin'emon about the tragedy that befell the country after Kaidou and Orochi took over, having witnessed firsthand the suffering Kaidou had brought to the people of Wano, particularly Tama, who he had befriended and then promised a better life to once the Beasts Pirates were gone. Once Kaidou came to Kuri and targeted Luffy's crew, the latter grew outraged and quickly engaged the Emperor in combat but was no match for him. After getting incarcerated at the Prisoner Mine and swearing payback, Luffy trained himself extensively in order to obtain enough power to truly injure Kaidou, finally attaining it through the help of Hyogoro, who had taught him how to utilize a higher level of Busoshoku Haki.

During the raid on Onigashima, after talking with Kin'emon and reiterating that he would fight for his friends' country, Luffy displayed his new ability against Kaidou, but still found it insufficient to bring him down. Luffy eventually figured out that Kaidou's toughness came from an advanced application of Haoshoku Haki instead, managing to replicate it and fight toe-to-toe with the Emperor for a brief period. Even after being knocked off of Onigashima, Luffy remained resolute that he would keep fighting Kaidou until he won.

Roronoa Zoro
Zoro, who seeks to be the World's Greatest Swordsman, once declared that he wanted to fight the World's Strongest Creature. As such, Zoro assisted Luffy during the fight against Kaidou and his wielding of Oden's former sword, Enma, caught the Emperor's attention, who had detected the familiar Haki emanating from it. Like the other Worst Generation pirates involved in the fight, Kaidou praised the Straw Hat swordsman's strength.

Kaidou was extremely shocked when Zoro somehow managed to channel Haoshoku Haki to slash him across the torso, acknowledging that the Pirate Hunter had been able to replicate Oden's feat from two decades ago.

Trafalgar Law
Law was aware of Kaidou's deal with Doflamingo and used this knowledge to forge an alliance with the Straw Hat Pirates, knowing that Luffy would attempt to take down the Four Emperors. Law used Kaidou's threat in order to force Doflamingo's hand and have the Warlord and Dressrosa ruler resign from his position, as part of his personal revenge plan against his former boss. With Doflamingo's defeat, Law continued with his original scheme to take down Kaidou alongside the Straw Hats.

As with Luffy, Kaidou became enemies with Law after finding out that the two pirates had destroyed his SMILE production. Like Luffy, Kaidou wants to kill Law, but does not consider him to be a real threat. He went to Kuri to apprehend them upon finding out they were there, but after defeating Luffy, Kaidou notably wanted to go back to Onigashima and get drunk rather than search for Law. During the raid on Onigashima, Kaidou grew to respect Law's strength, particularly his usage of the Ope Ope no Mi, which Kaidou had trouble defending against.

Eustass Kid
Kid encountered Kaidou when the latter fell out of the sky and landed at the Kid Pirates' hideout before coming face to face with the rookie pirate. Kid refused to submit to Kaidou and tried to fight him only to be defeated and captured. Kaidou then imprisoned Kid, hoping to eventually break his spirit. During his imprisonment, Kid is shown to hold a strong grudge against Kaidou and firmly told Luffy that he will be the one to defeat the Emperor. However, after seeing what happened to Killer, Kid decided to prioritize finding the rest of his crew and rejected Luffy's offer for an alliance. After getting his crew back, he joined Luffy and Law to take down Kaidou. However, he only did so for the glory of defeating him, not to support the Kozuki revolution.

X Drake
Upon entering the New World, X Drake immedietley sought to join Kaidou's crew; going as far as to attack one of his trsuted subordiantes on one of his favourite islands just to get his attention. He eventually succeeded and became one of his highest-ranking officers. He carried out many duties in Kaidou's name, such as quelling an uprising on the island he himself attacked and captured the instigator responsible, as well as hunting down a Sanji and those bearing the mark of the Kozuki Clan's rebellion.

In truth, however, X Drake is still a member of the Marines, specifically their SWORD branch. When the Ninja-Pirate-Mink-Samurai Alliance launched their attack on Onigashima, Drake defected from the Beast Pirates and thus on Kaidou himself.

Kurozumi Orochi


Kaidou and Orochi, the shogun of Wano Country, had been allies for over 25 years after Orochi bought his loyalty using the money previously borrowed from Oden. Their bond appeared to be strong, as Kaidou would attack anyone who threatened Orochi, and Orochi was extremely confident in having Kaidou's support, which allowed him to do anything, including opposing the World Government and exploiting them for his own gains. They were friendly enough to share drinks together in Orochi's castle. Kaidou was initially dismissive about Orochi's warning of the Kozuki Family's comeback and even poked fun at Orochi's paranoia. Nevertheless, when Orochi had shown proven information from his spy Kanjuro, Kaidou chose to believe Orochi, instructing the latter not to kill the time travelers as he wished to ask them information regarding Oden's journey to Laugh Tale. When he saw the broadcast of Orochi killing Shimotsuki Yasuie and the false laughter of the crowd watching, Kaidou expressed amusement at the shogun's cruelty.

In the end though, Kaidou was merely using Orochi as a pawn, and once Kaidou revealed his New Onigashima Project, he beheaded Orochi when the latter objected to it. Kaidou complimented Orochi's skill in exploitation, as the latter was the one who transformed Wano into a weapons factory for the former, but otherwise saw the former shogun as expendable in that role and wanted his own son Yamato to take over.

Unbeknownst to Kaidou, Orochi managed to survive from his beheading and became murderously furious towards Kaidou for betraying him.

Rocks D. Xebec
Kaidou's former captain during his time as an apprentice in the Rocks Pirates. The details of their relationship are unknown, but Kaidou seems to hold Xebec in high regard and respects him for his strength.

Wano Country Citizens
Kaidou is said to be revered in Wano as a "wise king" and protector of their realm, although this only seems to be the case among people who are loyal to Orochi. Anyone who becomes an enemy of Orochi also becomes an enemy of Kaidou, as seen when he attacked and killed the remaining daimyo for rebellion and attempted to kill the Kozuki Family and everyone associated with it. Thus, Kozuki Family loyalists consider Kaidou to be an enemy, and those who have allied with the family's survivors are working to take down Kaidou as well as Orochi. When Kaidou attempted to search Kuri for Luffy and Law while drunk, he mindlessly caused damage to Okobore Town without a second thought by flying through it.

When Kaidou announced the New Onigashima Project, he revealed that he had plans to enslave all of Wano's citizens, including those residing in the Flower Capital, to have them make weapons.

Abilities and Powers
People often say "If it's one-on-one, Kaidou will win." On land, sea, and air... among all living things, he is a pirate who is known as the "strongest creature"!!! As one of the Four Emperors, Kaidou is one of the four strongest pirates alive, renowned as the "Strongest Creature". Notably, he has a bounty of 4,611,100,000, which is the highest known bounty of any pirate currently alive and third highest in history, surpassed only by the bounties of the late Whitebeard and Gol D. Roger. As the Beasts Pirates' Governor-General, Kaidou has authority over a massive, 20,000-strong pirate organization, and due to his alliance with Shogun Kurozumi Orochi, he and his crew enjoy authority over and cooperation with thousands of Wano Country's samurai forces serving Orochi.Even during his start as a pirate apprentice at the Rocks Pirates, Kaidou was already formidable and after the fall of his captain and the disintegration of the crew only grow stronger throughout his life.

Kaidou attempted to take Whitebeard's life, something very few would dare, and subsequently had an encounter with Shanks, along with clashing against Big Mom two years later. The Five Elders mentioned Kaidou as one of the few people able to stop Blackbeard. His strength was also recognized by his fellow Emperor Big Mom, who could not fathom the idea of Monkey D. Luffy defeating him.

According to Trafalgar Law, Kaidou could easily kill Donquixote Doflamingo, a world-famous, extremely powerful pirate in his own right; Doflamingo himself, despite his normally always-retained fearlessness, was visibly distressed at the prospect of angering Kaidou. Additionally, Law speculated that his own crew and the Straw Hats allied together would only have a roughly 30% chance of bringing down Kaidou, though the statement is questionable seeing as, at that time, Law was not serious about fighting him. Kaidou defeated two other members of the Worst Generation, Eustass Kid and Killer, along with the rest of their crew, with seemingly no issue and refused to take Law and Monkey D. Luffy's alliance seriously regardless of their victory over Doflamingo, viewing defeating a Warlord of the Sea as nothing special. Kaidou's confidence was later proven to be warranted when he defeated Luffy with a single blow during their first fight.

Overall, Kaidou has been said to have only lost seven battles in his lifetime and has only been injured twice. As stated during his introduction, people consider it a certainty for Kaidou to win any one-on-one battle he takes part in, and even most groups and armies have little ability to take him down. When the daimyos rebelled, Kaidou crushed them, and when hundreds of samurai went to Onigashima to attack Kaidou 10 years ago, they were all killed. Before the fight on the rooftop of the Skull Dome even began, Kaidou was convinced that only Roger, Kozuki Oden, Whitebeard, Shanks, and his late captain were actually capable of fighting him seriously. During his fight against the Red Scabbards at Onigashima, Kaidou was having difficulties dealing with the Scabbards immediately in his Dragon form, but easily overpowered them all while in his human form, including the two Mink Kings, Inuarashi and Nekomamushi, whose strength both roughly rivals that of one of Kaidou's top men, Jack, and who both at the time, were in their Sulong forms. Kaidou also took on the Gecko Pirates 23 years ago and slaughtered all of them except for their captain, Gecko Moria.

Similar to the other Four Emperors members, Kaidou has many underlings and other pirate crews allied with him and is able to claim self-governing islands as his own territories. With Caesar Clown and Doflamingo as his associates, Kaidou has created an army of over 500 Artificial Zoan-type Devil Fruit users, known as the Gifters.

Physical Abilities
Befitting his muscle bulk, Kaidou is legendary for his supreme physical power as the strongest creature in the world. He is capable of swinging his kanabo hard enough to send a normal-sized person flying into the distance in one blow, and he broke past the tremendous defensive power of Luffy's Gear Fourth with great ease. He once sunk nine enormous prison ships singlehandedly. Sengoku once said that even as a mere apprentice in the Rocks Pirates, Kaidou was able to earn the respect of his vicious companions through his strength alone.

The most remarkable, Kaidou possesses nigh-indestructible durability, even without using Busoshoku Haki. He took multiple powerful hits from Luffy's Gear Third while in his dragon form and transformed back into his human form after being pummeled into the ground, and proceeded to receive a barrage of Gear Fourth hits that were even more powerful, yet only become sober and felt nothing more than annoyance, received no injuries, and was able to quickly get back up and counterattack without issue. This all changed once Luffy was able to improve his Busoshoku Haki from his training while in Udon and made Kaidou bleed with his newest Gear Third technique, which used advanced-grade Busoshoku Haki yet the damage was still low.

Kaidou also clashed with Big Mom continuously for one to three days, and emerged without any injuries or signs of fatigue, showing an incredible amount of stamina. While the Red Scabbards were able to accomplish the rare feat of drawing blood from him with their swords and attacks, these wounds were shown to have very little if any effect on him. He could withstand having his own immensely destructive Bolo Breath redirected at him by Raizo's Maki Maki no Mi, as well as assaults from Nekomamushi and Inuarashi's Sulong-enhanced attacks, Kawamatsu's Amano-gawa, Izou's Dangirigan, and Kikunojo's Zansetsu-gama, ultimately requiring Kin'emon, Denjiro, Inuarashi, and Ashura Doji to focus and coordinate their Togen Totsuka attacks together at his scar to finally inflict significant damage. However, Kaidou himself stated that the injuries were still shallow in comparison to when Oden inflicted him with a massive scar.

This durability has given Kaidou the reputation of being unable to die. He has been caught and tortured 18 times, and people as powerful as the Marines and other Emperors have attempted to execute him 40 times, only to fail as Kaidou survived every single attempt because every single execution weapon broke when being used on him. Most notably, Kaidou has jumped from 10,000 meters from the sky onto the ground, creating a massive shockwave strong enough to sink a large ship nearby, and emerged only with small headache; it has even become a hobby for him to attempt suicide, only for it to fail.

The first known time he ever suffered a significant injury was in a battle against Kozuki Oden, a legendary samurai who was dual-wielding two of the twenty-one Great Grade swords, Enma and Ame no Habakiri, gaining a scar on his body. During the raid on Onigashima, the Nine Red Scabbards were able to inflict considerable damage to him through teamwork and their improved strength and skills, though not to the same extent as Oden. When he was simultaneously attacked by Luffy, Law, Eustass Kid, Roronoa Zoro, and Killer, Kaidou also sustained damage. Even in his hybrid form, despite taking more lasting damage from the members of the Worst Generation, Kaidou continued fighting regularly, becoming more irritated than alarmed by their growing ability to damage him, showing that his endurance and pain tolerance are similarly anomalous like his durability. Kaidou was, however, visibly taken by surprise at Law's ability to continually bypass his defenses, as well as Luffy's and Zoro's growing skill with Haoshoku Haki and how both were actually able to seriously injure him. Despite his increased strength and skill with Haoshoku Haki, however, Kaidou was still capable of defeating Luffy singlehandedly, though Kaidou admitted that the fight caused him to get more excited than he had been in a while.

Despite his enormous size, Kaidou is extremely fast in combat and can move from one spot to another almost instantaneously. He completely blitzed Luffy in an instant while attacking him and appearing behind him afterwards. Another testament to his speed, he was fast enough to nearly once again blitz Luffy despite the latter perceiving the future using Kenbunshoku Haki, only barely avoiding a head-on attack.

Devil Fruit


Kaidou ate the Uo Uo no Mi, Model: Seiryu, a Mythical Zoan-type Devil Fruit that allows him to transform into a full serpentine Azure Dragon and a human-dragon hybrid at will. His full Beast Form is massive, roughly half the size of a small town, with extremely durable, blue scales.

As a dragon, Kaidou is capable of moving through the air by creating special clouds called "Flame Clouds" and using them as footholds. These clouds can also be used to lift other objects; they are even capable of lifting an entire island out of the sea. He can also release devastating blasts of fire from his mouth, which can instantly deal significant damage to, if not fully obliterate, large structures. Aside from his fire breath, Kaidou can also release other elemental attacks from his mouth; he can release bolts of lightning by roaring, or invisible, sharp wind blades by blowing. By twisting his massive body, Kaidou can create tornados which can enhanced his attacks.

Kaidou has mastered his Devil Fruit powers to the level that he can access some of his draconic abilities without needing to transform, such as generating Flame Clouds to levitate Onigashima. He was even able to do so while battling against five members of the Worst Generation alongside Big Mom.

Haki
Kaidou is one of the few people in the world capable of using all three forms of Haki. Law stated that he could not directly move Kaidou around inside his "ROOM" due to Kaidou's Haki being too strong.

Haoshoku Haki


Kaidou possesses immense mastery in Haoshoku Haki, which was first displayed when he clashed against fellow Haoshoku Haki user Big Mom, resulting in a lightning-like effect that shook Onigashima and split the heavens. Most notably, Kaidou is one of the few powerful individuals able to imbue their Haoshoku Haki into objects such as his kanabo, which is signified by thin lightning-like streams of dark energy emanating from the imbued areas. This imbuement allows him to dramatically increase his attack power as a supplement to his natural physical strength and Busoshoku Haki; this degree of strength has allowed him to quickly knock powerful pirates like Luffy, Zoro, and Law unconscious with only one or two strikes.

Busoshoku Haki
Kaidou is an immensely powerful user of Busoshoku Haki, which he is capable of imbuing into his kanabo. In the battle on Onigashima, similarly to Katakuri, his Busoshoku Haki was strong enough to damage Luffy who hardened both of his arms. He is capable of utilizing the advanced application of projecting his Busoshoku Haki out from his kanabo, allowing him to strike opponents many meters in front of him with devastating power without the need to make direct contact, and the attack power can be further increased if the kanabo is imbued with Haoshoku Haki.

Kenbunshoku Haki
Kaidou possesses Kenbunshoku Haki, which he first demonstrated when he sensed the "voices" of the supernovas in the wake of his and Big Mom's combined attack which enabled him to tell they were still alive. In the rare event that he faces an attack that will harm him, Kaidou can also use this Haki to help him dodge.

Weapons


Kaidou wields a large, black, spiked kanabo named Hassaikai as his signature weapon, which he already possessed during his apprentice days in the Rocks Pirates. Thanks to his massive strength and ability to imbue the club with Busoshoku and Haoshoku Haki, Kaidou can perform incredibly powerful strikes by swinging it, allowing him to produce large shockwaves, severely injure foes, knock mighty adversaries unconscious with a single hit, and send people flying off into the distance.

Shuron Hakke
By consuming alcohol, Kaidou is able to enter a state called Shuron Hakke. In this state, his movements become more unpredictable, he switches rapidly between his Zoan forms, and his Haki becomes stronger. The Shuron Hakke state has various modes based on his drunken moodswings.


 * Warai Jogo: A laughing drunk mode. When using this mode against Luffy, Kaidou attacked him with a version of his Ragnaraku technique. In the Viz translation, this is called Lightning Hammered.
 * Ochikomi Jogo: A depressed drunk mode. When using this mode against Luffy, Kaidou attacked him with Tatsumaki Kaifu. In the Viz translation, this is called Drowning His Sorrows.
 * Naki Jogo (き): A crying drunk mode. When using this mode against Luffy, Kaidou attacked him with Raimei Hakke. In the Viz translation, this is called Tears in His Beer.
 * Okori Jogo (り): An angry drunk mode. When using this mode against Luffy, Kaidou attacked him with Bolo Breath and Gundari Ryuseigun. In the Viz translation, this is called Drunken Rage.

Major Battles

 * Rocks Pirates vs. Roger Pirates and Marines (unseen)
 * Kaidou vs. Gecko Moria's first crew (unseen)
 * Beasts Pirates and Kurozumi Higurashi vs. Kozuki Oden, the Nine Red Scabbards, and Shinobu
 * Kaidou vs. Kozuki Oden
 * Kaidou vs. Ashura Doji and Denjiro (unseen)
 * Kaidou vs. Shanks (unseen)
 * Kaidou vs. Eustass Kid and Killer (unseen)
 * Kaidou vs. Speed
 * Kaidou vs. Monkey D. Luffy
 * Kaidou vs. Charlotte Linlin
 * Beasts Pirates and their allies vs. Ninja-Pirate-Mink-Samurai Alliance and Kid Pirates
 * Kaidou vs. The Nine Red Scabbards (minus Kanjuro) and Izou
 * Kaidou, Linlin, Zeus, Prometheus and Napoleon vs. Luffy, Roronoa Zoro, Kid, Killer and Trafalgar D. Water Law
 * Kaidou vs. Kin'emon
 * Kaidou vs. Yamato
 * Kaidou vs. Luffy, Yamato and Momonosuke
 * Kaidou vs. Luffy

Name
Kaidou's name was officially romanized as "Kaido" in One Piece Green: Secret Pieces; however, it is shown to be spelled "Kaidou" in his bounty poster in the manga as well as in his Vivre Card - One Piece Visual Dictionary entry.

Epithet
The "hyakujū" (百獣) part of Kaidou's epithet is an idiomatic noun meaning "all kinds of beasts/animals" (referring to the animal kingdom), combining the kanji for "hundred" (百) and "beast" (獣); it is usually found in the Japanese title attributed to the lion, "hyakujū no ō" (百獣の王), meaning "king of beasts". With Kaidou's title an obvious derivation ("Kaidou" replacing "king"), it can be translated as "Kaidou of the Beasts". In the VIZ manga translation, Kaidou is instead called "Kaidou, the King of the Beasts" to make the connection more obvious.

Anime and Manga Differences
During his clash with Big Mom at Onigashima in the manga, he was shown wearing his shirt. In the anime, he is not.

Playable Appearances

 * One Piece Thousand Storm
 * One Piece Treasure Cruise
 * One Piece Bounty Rush
 * One Piece: Pirate Warriors 4
 * Jumputi Heroes
 * One Piece: Burning Will

Support Appearances

 * One Piece: Great Pirate Colosseum

Trivia

 * As with Big Mom's, Kaidou's first-shown silhouettes prior to his debut greatly differed from his actual looks revealed much later:
 * His first silhouetted self was seen when the Four Emperors were first explained by Garp in Water 7, depicting Kaidou as having a much wider face, a pointier, beak-like nose, and a huge, evil-looking grin.
 * When Jinbe briefly talked about the Four Emperors at the end of the Fish-Man Island Arc, the anime showed a similar silhouette of Kaidou as the earlier one, with his hair much puffier and wavier than it would turn out to be.
 * The person who provided what turned out to be Kaidou's voice in Episode 630 is uncredited.
 * The anime episode of Kaidou's debut first aired on May 1, which is also Kaidou's given birthday.
 * Kaidou's bounty is the highest currently revealed active bounty, the second highest among the Four Emperors past and present (below Whitebeard's), and the third highest known overall.
 * His bounty (like the other Emperors') also represents a goroawase-type numerical pun: in 4,611,100,000, the digits 110 as the whole number "one-hundred-ten" would be read as "hyakujū" (百十), making it homophonous with the "Beasts" (百獣) part of Kaidou's epithet.
 * Among the Four Emperors, Kaidou is the only one not yet seen as a child.
 * Kaidou possesses some notable parallels and contrasts to his arch-enemy Kozuki Oden. Both were born 59 years ago and fathered their intended successors, Yamato and Momonosuke, 28 years ago. However, while Oden wanted to leave the confines of Wano and explore the sea and later open Wano's borders, Kaidou started out as a voyaging pirate and now has a great interest in being based in Wano and keeping its borders closed. Interestingly, however, the paths of each of their children resemble that of the other parent; despite having been out at sea, Momonosuke wishes to fulfill his birthright and take control over Wano as its shogun, while Yamato has been trapped on Wano and wishes to set out to sea. Additionally, Momonosuke has eaten an artificial copy of Kaidou's Devil Fruit, while Yamato wishes to actually adopt the identity of Oden.
 * Kaidou seems to be inspired by oni, ogre-like yōkai who are among the greatest icons of Japanese mythology:
 * Oni are usually depicted as having a giant, hulking frame, one or multiple horns on their heads, wild hair, and a fierce visage, traits shared by Kaidou.
 * Like Kaidou, oni are said to possess immense body strength. In addition, they are often depicted carrying kanabo as their signature weapon, like Kaidou does.
 * Kaidou's residence on Onigashima (literally "island of oni") is based on the Japanese folktale hero Momotarō's tale, wherein Momotarō, upon maturing into adolescence, went to defeat a band of oni dwelling on an island of said name.
 * A resemblance of Kaidou's character can be also observed to a particular oni of Japanese myth, Shuten-dōji, whose story is one of Japan's most popular oni tales (and whom Ashura Doji is also based on):
 * Shuten-dōji was a giant, powerful oni and leader of a bandit gang who lived at Mt. Ōe in his fortress. He was born human, but as a child was referred to as a "monster child" (怪童) for his supernatural strength and wit (which Kaidou's name may derive from, with the word "kaidō" also translatable as "an unusually large or strong youth").
 * Since his youth, Shuten-dōji had a matchless thirst for sake (hence his name that means "sake-drinking boy") and after becoming an oni would often go on drunken rages, similar to Kaidou's own drunk persona. In fact, Kaidou's sake gourd has the kanji for "heaven" (天) on it, which is also contained in a variant of the name "Shuten-dōji" (酒天童子).
 * Kaidou's name may further derive from Kintarō, also called Sakata no Kintoki, another folk hero of Japanese myth. Not only is Kintarō connected to the figure of Shuten-dōji (capturing him at one point), one of his other (Edo-period) names is "Sakata Kaidōmaru" (坂田怪童丸).
 * Kaidou's rank as head of the Beasts Pirates is called "governor-general" (総督), which is also translatable as simply "governor" or "viceroy". In a Japanese context, such term can refer to certain military commanders that were active in Japan from the Bakumatsu to the early Meiji era. Additionally, from 1910 to 1945, Japanese-administered Korea had a governor-general, as did Japanese-administered Taiwan between 1895 and 1945.
 * Kaidou's belt, a twist of white rope with zigzag paper streamers, is based on the ropes (綱) traditionally worn by yokozuna (the highest-ranked sumo wrestlers, hence their name) during their entrance ceremonies so as to denote their rank. Said belts are a variation of the much larger shimenawa used to mark off sacred Shinto spaces like shrines; similar to the shimenawa, the yokozuna belts hold religious meaning as objects of purification.
 * Kaidou's Wano-bound reputation as a "Wise King" (明王) is based on the Wisdom Kings (their Japanese name), who are Vajrayana Buddhist deities.
 * Kaidou is currently the only one of the Four Emperors whose flag ship has not been seen or named.
 * In the 6th and 7th fan popularity polls, Kaidou was ranked 97th and 65th, respectively.
 * Kaidou's favorite food is alcoholic beverages.