Summary:
Everyone has heard about Kozuki Oden traveling to Laugh Tale. Robin realizes that Oden must have known about the Void Century. Kin’emon and his charges want to fight back. They ask their allies for help and they accept. However, Luffy refuses due to Momonosuke being the supposed leader of Wan. After Momonosuke’s request for Luffy’s help in defeating Kaido, he then accepts. The Ninja-Pirate-Nink-Samurai alliance is formed to defeat Kaidou together.
As everyone reacts to finding out that Momonosuke’s father, Oden, who was executed, traveled to Laugh Tale on Gol D. Roger’s ship, Robin realizes that Oden must have known about the Void Century, which Ohara archaeologists have spent their lives studying. Zoro believes that this is why Kin’emon’s group of samurai were targeted by Doflamingo and Caesar, who have ties to Kaida, though Oden kept all the information to himself for the safety of his people.
Kin’emon, like all the other charges, say they plan to fight because of Oden’s last words, which were, “Open Wano Country!” The reason the samurai came to Zou is to ask their allies, the Minkas, to help them fight and the rest of the samurai, except for Momonosuke, asked Law and Luffy for help. The rest of the Straw Hats accept the offer without hesitation, but Luffy declines the request. As the group tries to knock some sense into their captain, Luffy calls out to a crying Momonosuke and says that he should ask for their help if he is the supposed leader of Wano country. Momonosuke steps out and asks for Luffy’s help to take down Kaido as he is too small now, but he still wants to protect all of his charges. Luffy then accepts Momonosuke’s request and the rest of the leaders band together to form the Ninja-Pirate-Nink-Samurai Alliance to defeat Emperor Kaido.
After Luffy’s group learns that Oden was part of Roger’s crew, we get a recap of the Void Century.
The anime adds the following:
Usopp asked the samurai if they knew the secrets of the world after Zoro explained the reason why Doflamingo and Caesar were chasing them.
After the samurai and the two Zou rulers reveal Oden’s will to open Wano Country to the world, Brook explains to Chopper how Wano Country is closed.
Right after Inuarashi and Nekomamushi explain that they will use the true power of minks the next time they face the Beasts Pirates, Chopper tells Nekomamushi to take his injuries more seriously.
Kanjuro and Raizo also ask Luffy for help.
Franky and Chopper also encourage Luffy to join the samurai in their cause.
After Kin’emon asks Luffy for help, the anime shows Luffy refusing more times than in the manga.
When Nami tries to hug Momonosuke in the manga, Brook angrily states that she shouldn’t. He doesn’t say anything in the anime.
Momonosuke’s shot of the day Kaidou sacked Wano Country is extended to show the large fire started by the flaming arrows, Kin’emon’s panicked reaction, Lord Oden calling out as he tried to escape the flames, and the moment Momonosuke’s mother was killed.
When Momonosuke encounters Kaidou, Kaidou is shown in full and has his mace rather than a glimpse of his mouth.
Kaidou’s eyes are clearly shown during Momonosuke’s shot, glaring at him with hatred. For the first time in the manga, a clear look was shown in Kaidou’s eyes as he vented his anger at the loss of SMILES.
After Kin’emon comments on how Luffy treats Momonosuke like an adult, the manga shows Inuarashi saying how admirable it was. In the anime, it’s Raizo instead.