Oda revealed that Ulti and Page One were adopted by Kaido

Question: Are Ulti and Page One real siblings? Page One seems to call her with a term that feels more like it could also be said to an older female friend, not just big sister, so I’m very curious about the two!

Oda: Yeah, they are brother and sister. It appears their father was a pirate too, but he passed away. Kaido knew their father, so he ended up taking the two with him afterwards.

Ulti was very smart. She stole two devil fruits that Kaido had and made both her and her brother into capable forces, so that they could survive in this pirate crew, where the strong make it and the weak get devoured. They even managed to become Tobiroppo.

Straw Hats will end up having more Conqueror’s Haki users than the legendary Rocks Pirates!

Yamato will inherit Kaido’s Will at the end of the Wano Arc