Yamato Delgado/Daiwa is a B-DaPlayer at the young age of 11. Up until he was 5 years old, he was living with cats that had raised him since birth. A young girl, Mie Delgado, adopted him.

Yamato Delgado's only dream was to play B'Daman-the official sport of the B'DaWorld, and according to Mie, Yamato was destined to be a B-DaPlayer. Yamato's dream comes true when he's chosen to wield the most powerful B'Daman ever, the legendary Cobalt Blade. Only he has skills to harness its power.