Summary:
Kid and Killer refuse to join Luffy’s alliance and leave the prison. Doji shows the graves of the people lost in Onigashima ten years ago, after which he joins the alliance. Momonosuke finally appears to the prisoners, who also join the alliance.
Killer uses the keys to unlock Kid’s handcuffs. Kid goes to Luffy who is lying on the ground. Luffy invites Kid to join the alliance, but Kid declines. He uses his Devil Fruit power to create an arm out of magnetic parts and then breaks down the prison gate. He and Killer leave.
Doji takes Kin’emon and Inuarashi to a cemetery with some tombstones. Doji explains what happened. Ten years after Oden’s death, Doji’s men are impatient for the Nine Red Sheaths to return. Unwilling to wait another ten years, they beg him to allow them to leave immediately and face Kaida in Onigashima. Doji argued against this, stating that they would be completely powerless against Kaidou, so their deaths would be useless.
One of the men explains the meaning of the word “sunacchi”; it was an abbreviation of the phrase, “Namae o sutero, chie o sutero.” (“Throw away your name and your wits.”) A phrase indicating not to be afraid of danger and to rush forward for one’s cause. Against Doji’s orders, they set sail for Onigashima. As he warned, the soldiers were decimated by Kaidou’s garrison and died in vain before being buried in the graveyard. Back in the present, Doji and his men decide to join Kin’emon’s alliance to take down Kaido.
In Udon, the prisoners begin to doubt Luffy that he is a pirate like Kaidou. They also doubt the prophecy and that the Nine Red Sheaths have actually returned from the past. Momonosuke hides with Luffy, who is resting in a cell while Chopper prepares the medicine. Although Momonosuke is hesitant to appear before them, Luffy throws a boulder at him to chase him out.
Momonosuke is spotted by the inmates and immediately recognized. The prisoners bow to him and Momonosuke gives a speech urging them to help fight Kaidou. Now convinced that the Nine Red Sheaths have truly returned, they join the cause to free the land of Wano and depose Orochi.
The anime adds the following scenes:
Chopper found Luffy after conquering Udon.
The killer freeing Kid from his bonds.
As Kid creates a mechanical arm, the prisoners notice metal fragments floating in the air.
During the Ashura sequence to the past, a member of the Beasts Pirates who destroyed the well also attacked a man and a woman carrying a child.
The screen shows Luffy throwing a boulder at Momonosuke.
As the prisoners bowed to Momonosuke, he has a moment of doubt before gathering his courage.
Momonosuke’s speech to the prisoners is shown.
In the manga, Luffy asking Kid to join the fight against Kaidou and Kid rejecting his offer were shown as flashbacks.
As Ashura watched his comrades sail to their doom in the manga, he yelled at them to come back. In the anime, she just cries and screams.
The inmates’ initial distrust of Luffy is expanded upon in the anime.
When Luffy speaks lowly about Momonosuke in the manga, the boy was about to pounce on Luffy and was held back by Tama. In the anime, Momonosuke is about to punch Luffy, but Tama stands in his way.