The Straw Hats meet Johnny and Yosaku, who direct them to the restaurant ship Baratie, a sort of "floating oasis" in the middle of the ocean, where they meet Sanji. However, a pirate admiral named Don Krieg sets his sights on the Baratie as a replacement for his devastated fleet, and the restaurant soon comes under siege.
The arc begins with the Straw Hat Pirates (Luffy, Zoro, Nami, and the newly-joined Usopp) checking out their new pirate ship as well as designing a Jolly Roger for it. As a test of the ship's capabilities, Luffy and Usopp test out one of the cannons on board by shooting at a rock formation. However, unbeknownst to them, two pirate hunters happen to be on the rock, and one of them attacks the ship in retaliation. Luffy fights him, but Zoro points him out to be a friend of his. It is here the Straw Hats meet Johnny and Yosaku, who were on the rock that was shot at. After the Straw Hats apologize and Nami cures Yosaku of his scurvy, the crew realizes that they are going to need a cook for the ship to maintain the healthy quality of their food stores before they can go to the Grand Line. To repay the favor for helping them, Johnny and Yosaku tell the crew of a floating restaurant in the middle of the ocean where they might find a cook, helpfully navigating the crew to the aforementioned restaurant, the Baratie.
Upon their arrival, the group runs into trouble with a Marine Lieutenant, Fullbody. In the scuffle between the two, Luffy accidentally redirects a cannonball into the Baratie's roof. While Luffy tries to make a deal with the captain, head chef and owner of the ship, Zeff, to pay for the damages caused to the roof, we meet Sanji, the assistant chef. Sanji has an encounter with Fullbody as well, when he almost kills Fullbody for insulting the Baratie's food. However, an even bigger incident occurs when a pirate named Gin, a member of Don Krieg's armada who was being detained by Fullbody, comes onto the ship demanding food. Although denied food, beaten, and thrown out of the restaurant by the crew, Sanji secretly serves the man a savory meal, saving Gin from starvation. Despite this act of kindness, when Gin leaves and returns to his ship, he tells Don Krieg about the Baratie. After hearing about the ship, Don Krieg comes to believe that taking over the Baratie is a key step in resurrecting his fleet.
Eventually, Krieg comes to the restaurant under the pretense that he will not hurt anyone if he receives some food. Of course, Krieg attacks the cooks onboard and claims the Baratie as his own, since his original ship and his entire fleet were destroyed seven days into the Grand Line by a mysterious figure. Just as important, his crew is on the verge of death from starvation. Surprisingly, Zeff gives a sack of food to Krieg and warns his cooks about the upcoming battle. The Baratie raises its battle fins, which protect the restaurant portion of the Baratie, as the cooks and the Krieg Pirates begin to fight.
In the midst of the battle, Luffy (who has been working as "Chore Boy" to pay off the damages to the roof) and the other Straw Hats try to get the Going Merry away from the battle. Only then do they realize that Nami double-crossed them and stole their ship and treasure, with Zoro, Usopp, Johnny and Yosaku preparing to go after her. However, their plans are brought to a halt when Krieg's galleon is suddenly sliced in half. Through the wreckage of the ship sails the mysterious figure that Zoro instantly recognizes as Dracule "Hawk-Eyes" Mihawk, one of the Seven Warlords of the Sea and the greatest swordsman in the world. Zoro decides to try and defeat Mihawk to gain the title of greatest swordsman in the world, but is clearly outmatched by Mihawk's strength.
However, Zoro impresses Mihawk with his courage and honor. As a result, Mihawk spares Zoro's life (so that he can become a better swordsman and face him again someday). After the loss, Zoro vows never to lose again before setting off with the other Straw Hats to go after Nami. Luffy stays behind to help the Baratie, with Zeff accepting Luffy's request for his debt to be repaid as the reward for his assistance against the Krieg Pirates. With that, Mihawk departs and Krieg directs his attention back to the Baratie.
The cooks find that Krieg's pirates are not pushovers, and the battle is not going well for the Baratie's cooks, until Sanji joins the fray. However, the tide turns back in Krieg's favor when his second mate, "Iron Wall" Pearl, arrives. At first, Sanji has the upper hand, but after Pearl nearly burns down the ship, Gin is forced to hold Zeff at gunpoint to keep Sanji from fighting back, allowing Pearl to thrash Sanji around. It is during this point we learn about Sanji's past. Surprisingly, Gin saves Sanji from Pearl, claiming he wants to kill the cook himself. The two fight briefly, but with Sanji still injured from his fight with Pearl, Gin gains the upper hand. However, Gin cannot bring himself to kill Sanji, which infuriates Krieg. As a result, he tries to kill Gin with a poison gas grenade known as MH5, which Gin barely survives. This act upsets Luffy, who attacks Krieg. What follows is a long fight on the wreckage of Krieg's ship.
Krieg uses everything in his armor's arsenal to try to kill Luffy. However, Luffy counters and powers though each weapon, finally finishing off Krieg by slamming him into the side of the Baratie with his legs (although Krieg won't stay down until a final punch in the gut by Gin stops him in his tracks). However, Krieg's final attack with his iron net sends Luffy into the ocean. Sanji saves Luffy from the ocean, and Gin and the rest of Krieg's pirates sail away on a small dinghy.
In the final act of the arc, Zeff and his cooks try to persuade Sanji to leave by telling him a soup he cooked tasted awful. Sanji almost falls for it, but then overhears them when they actually say it tastes delicious. He remembers his dream of finding the All Blue and finally agrees to join Luffy's crew. Just as he makes his decision, Yosaku returns (traveling on a panda shark) and warns Luffy that Nami is heading towards a dangerous island. Zeff and the Baratie cooks all give Sanji a tearful send-off before he, Luffy, and Yosaku head out to catch up with the others.
Usopp's cannon wielding earns him his role as the sniper of the Straw Hats.
Nami's betrayal shows her hidden nature and hints toward her past and her relationship to the fish-man pirate Arlong and his crew. Her obsession with looking over Johnny and Yosaku's copy of Arlong's wanted poster would help the two suspect a connection between Nami and Arlong, which allows them to successfully predict Nami's destination.
The crew gets their cook, Sanji, who is considered their third strongest fighter.
Sanji's past with Zeff is shown. However, his earlier history with his family will not be revealed until the Whole Cake Island Arc. Furthermore, Sanji's devotion and love for his father figure would also be put at risk by his birth father Judge.
Zoro loses his duel to Mihawk and vows never to lose again, leaving him with his first permanent battle scar and his two unnamed swords destroyed, leading to him receiving newones two story arcs later in the Loguetown Arc.
Jinbe is mentioned, he will later appear in the Impel Down Arc and later become the Helmsman of the Straw Hat Pirates.
In the manga, after Nami asks Luffy and Usopp to get limes to cure Yosaku's scurvy, they convert it into a drink which helps Yosaku wake up. In the anime however, Luffy and Usopp instead try to squeeze the juice from the limes into Yosaku's mouth, before stuffing them into the mouth and the choking effect causes Yosaku to wake up.
In the manga, when the Straw Hats and Johnny talk about recruiting a cook for the Straw Hats they are on the Going Merry's deck. In the anime this was moved into the ship's lounge instead.
In the manga, when Mihawk is mentioned by Gin and Zeff, the chefs had a recollection of a customer they once had called Drunk Eyes (chapter 49), which turns out to not be the "Hawk-Eyes" that Johnny is referring to earlier (chapter 42). This confusion isn't mentioned in the anime, and Drunk Eyes was left out.
In the manga, when Fullbody notices that Johnny and Yosaku are on the ship and insults them, Johnny and Yosaku attempt to attack him, but get beaten up instead, with Johnny's wanted posters falling on the Going Merry's deck. In the anime, Johnny gets angry at the insult and simply throws some wanted posters on the deck.
In the manga, when the Straw Hats are fired upon by the Marines, Luffy deflects it with a simple Gomu Gomu no Balloon. In the anime, he invents a new technique called the Gomu Gomu no Pachinko.
In the manga, Lines the marine is not shown after being shot by Gin, and is presumed to be dead. In the anime, he can be seen crawling out of the Baratie alongside Fullbody.
In the manga, Gin accepts Sanji's fried rice almost immediately. In the anime, he initially rejects it out of pride, and Sanji has to convince him to eat it.
In the manga, Luffy stays "employed" at the Baratie for two days before Don Krieg arrives. In the anime, it is four days.
In the manga, when Sanji announces his intention to cook for the rest of Don Krieg's men, the rest of the Baratie's cooks point pistols at him. In the anime, the cooks instead point enormous kitchen utensils, such as forks and knives, at Sanji.
In the manga, during the battle against Don Krieg, Krieg at first feints using the MH5 by using a shuriken bomb instead. This is not shown in the anime.
In the manga, during the battle against Don Krieg, when Gin subdues Zeff, he does it by breaking Zeff's peg leg and pointing a gun at him. In the anime, Gin simply knocks over Zeff and points the gun at him.
In the manga, during the flashback, Zeff loses his leg by eating it. In the anime, he loses his leg by cutting it off when he was caught in some sinking ship debris.
The amount of time Sanji and Zeff stay shipwrecked on the island is shorter in the anime, which is marked with a chalk for 47 days instead of the caption, stating it was 85 days. Also in the manga, a passing ship's crew fails to hear Sanji's cries the first time it comes around, before coming back several months later. This is skipped in the anime, and instead they are immediately rescued when it comes by on the same day Sanji learned that Zeff lost his leg (which is 15 days earlier in the manga).
Once Zeff and Sanji start the Baratie, Sanji picks up smoking and claims that "he's a man now". This was cut out of the anime, as to not tell viewers smoking equals maturity.
In the manga, just as Zoro is preparing to battle Mihawk, at the scene with the Going Merry, Nami sadly hopes that she will get to see her new friends again and is happy that she will soon be free, before she sadly calls out to Bell-mère. In the anime, this scene is instead moved to after Luffy defeated Don Krieg.