Yamato, who was raised by cats until he was five, has only dreamt of owning a B-Daman and playing the sport. When his dream comes true and is given the legendary B-Daman, Cobalt Blade, will Yamato have what it takes to control it from those who wish to steal it from him?

In a rematch against Gray, Yamato learns how to better control Cobalt Blade. During the match, Bull's ""dark side"" makes his first appearance in order to steal both Cobalt Blade and Chrome Zephyr. It is up to Gray and Yamato to keep that from happening. Can Gray and Yamato put their differences aside to stop him?