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.

Before Yamato started out on his adventures, he met Gray and Bull. While on his way to see the greatest B-Daman inventer in the world, Yamato met Terry and they became good friends and traveled to Armada's house together.

On his travelings, Yamato met more friends, and foes, and he is on his way to defeat the evil NeoShadow Alliance with his newly created, legendary Cobalt Saber, and to become the B-DaChampion.