Starting with One-Punch Man: Always Evenly Matched

Bai Yu is bound to the Wish System. From then on, he accepts commissions in every anime world and fulfills the wishes of those who entrust them to him.

Saitama: “If there’s anyone in this world who could give me a real fight, it has to be Bai Yu.”

Yujiro Hanma: “Bai Yu? Heh heh heh. What a dutiful child.”

Tsunade: “What? Bai Yu!! I still haven’t settled the score with that guy for peeking at me while I was bathing!”