Summary:
Yamato tells Momonosuke and Shinobu about his relationship with Ace. Ace initially attacked Onigashi to take down Kaido, but befriended Yamato.
Long summary
Sanji tries to escape but is caught by Black Maria’s silk. Black Maria is revealed to have the power of the Devil Fruit, which allows her to transform into Rosamygale grauvogeli, an ancient spider. Meanwhile, Luffy fights furiously against the Beasts Pirates, and the darkened enemy who confronted Jinba hears. The enemy is revealed to be Who’s Who, who has transformed into a saber-toothed tiger. Who’s-Who implies that, like Jinbe, he worked for the World Government.
In the warehouse, Yamato bandages Shinobu’s wounds. At this point, Yamato reveals more about his experiences with Ace.
Leading his own pirate crew, Ace attacked Onigashi to rescue the kidnapped children. Ace fought his guardian Yamato where it was revealed that Kaidou was on a mission with his top officers. While Ace’s subordinates rescued the children and sent them back to the mainland, Ace continued his fight. Yamato revealed his past.
When Ace was a child, his father Roger was despised by people. Ace began to question if his life was worthless when his father was so rejected. Yamato also revealed his past; because he dreamed of living free like Oden, Kaidou put handcuffs on him that would explode if he left the island. Ace encouraged Yamato to do what he wanted against Kaidou’s wishes. In anger, Yamato destroyed Kaidou’s dragon statue.
Ace and Yamato form a friendship. As they watched the sunset, Ace told Yamato about the outside world, including his brother who would rise as a powerful pirate.
Yamato finishes his story saying that Ace died two years ago but his brother Luffy inherited his will. Yamato anticipated Luffy’s return so he could take down Kaido. Meanwhile, Tama reveals to Nami that she also knew Ace.
The anime adds the following:
Ace and his crew are seen arriving at Onigashima.
The moment the Spade Pirates rescue the kidnapped children is seen.
A brief flashback to Yamato and Kaido.
The anime expands on the following:
The battle and later conversation between Yamato and Ace.