Chapter 999

Chapter 999 is titled "The Sake I Brewed to Drink With You".

Short Summary
Around three years ago, Ace came to Onigashima with his crew to fight Kaido, and dueled Yamato as Kaido was on an expedition. During the course of their fight, Ace grew to learn of Yamato's desire to leave Wano, and together the two of them damaged Kaido's great dragon statue. Back in the present, Marco takes Zoro up to the Dome's roof, confronting King and Queen. While doing this, he remembers how Whitebeard refused to go back to Wano and take on Kaido, and would not let Ace do so alone, with the crew's reasoning being that the damage and casualties would be too great even for the sake of avenging Kozuki Oden.

On the Dome's roof, the recently arrived Big Mom tells Kaido to kill all the Straw Hats he pleases except for Robin, whom she needs to read the Poneglyphs. Kaido tells her about his intention of placing Onigashima at the sight of the Kozuki Family's castle in the Flower Capital, and she inquires about the location of his Road Poneglyph, wanting him to repay the favor she did by giving him his Devil Fruit on God Valley 38 years ago.

Long Summary
In a flashback, Portgas D. Ace and his crew, the Spade Pirates, came to Wano, where despite Ace's crewmate's pleas, he immediately started fighting Yamato. Ace demanded Yamato reveal themselves before Yamato tells him to do so first. Ace introduces himself to them and announces he has come to take Kaido's head. Yamato reveals to Ace that Kaido and his crew have left Wano on an expedition so he won't find any member of the Beasts Pirates on the island while also revealing Kaido is Yamato's father. Yamato tells Ace to stand down as Ace notices the explosive cuffs on Yamato's wrists.

Ace's crew tell him that they should leave and return the abducted children to their families. Ace, however, says that it doesn't make sense someone as strong as Yamato isn't the captain and wants to settle the fight. Yamato agrees saying they have been bored for a while. They clash again and Ace yells that Yamato can't choose their father, and if they hate Kaido so much, why are they not only allowing him to chain their wrists, but their heart as well. This moves Yamato to strike the Dragon statue and declaring they wish they could leave Wano and sail out to sea on adventures the way Kozuki Oden did. Ace becomes so impressed by this that he also strikes the statue with his fire.

Afterwards they share a bottle of sake where Yamato tells Ace once they get the cuffs off they want to leave before asking about what it is like outside of Wano. Ace admits there are many people making a name for themselves such as Cavendish, and while he himself is making a name, there are many others, such as Eustass Kid, Trafalgar Law, and Capone Bege, but the toughest one of them all hasn't set out yet: his brother, who Ace is confident will be massive.

In the present, Yamato explains to Momonosuke and Shinobu how the both of them broke the dragon statue and how Kaido was furious. Momonosuke was surprised to hear that a previous pirate tried to save Wano before asking about what Yamato meant when they referred Kaido as their "father". Yamato reveals their heritage, causing Momonosuke and Shinobu to back up in a panic. Yamato tries to calm them down by saying that they hate Kaido and consider themselves Kozuki Oden, but that just confuses them even more. Nevertheless, they still accept Yamato as a friend and ask why they were telling them about Ace. Yamato explains that Ace died two years ago and proceeds to talk about him again. In another location, Tama reveals to Nami her own history with Ace and how hard she was working to become a kunoichi as well as how ungently Luffy told her he had died. Nami apologizes, saying that is just how Luffy is before saying that Ace's death was painful for Luffy too, which confuses Tama.

On the Performance Floor, Queen orders his men to stop Marco, who reluctantly do so despite him healing their disease. Marco decides not to face Kaido yet and tells Robin and Brook to run into the castle while he takes to the skies carrying Zoro in his full phoenix form.

Chapter Notes

 * The past with Yamato and Ace is shown.
 * Kaido and his top-ranking subordinates were away from Onigashima at the time so Ace never encountered Kaido.
 * The broken dragon statue in the storeroom is revealed to have been in fact destroyed by Yamato, with Ace only taking responsibility afterwards in order to give Kaido a warning.
 * Marco transforms and flies with Zoro to the roof while Brook and Nico Robin run up the castle.
 * King and Queen block Marco’s way.
 * The Whitebeard Pirates found out about Oden’s death several years after it happened. They talked about going to war with Kaido, but Edward Newgate never approved.
 * Momonosuke and Tama learn that Ace was Luffy’s brother.
 * Momonosuke also learns that Yamato is Kaido’s daughter and Ace was Roger’s son.
 * Big Mom has reached Kaido.
 * Zeus and Prometheus recharge and are now enlarged.
 * Big Mom requests Kaido to keep Robin alive as she decides not to wait for Pudding’s power to awaken.
 * It is revealed that Big Mom gave Kaido the Uo Uo no Mi on the day the Rocks Pirates fell.

Trivia

 * The title of the chapter may be a reference to poem No. 555 from the 4th volume of the Man'yōshū. The full poem is "The sake I brewed to drink with you, I drink alone in the field of peace, for I no longer have a friend to drink it with." (君がため醸みし待酒安の野にひとりや飲まむ友なしにして).