The show is about Yamato Delgado (Daiwa in the Japanese version), who gets the legendary Cobalt Blade. He and his friends use the sport of B-Daman to fight the Shadow Alliance. This show takes place in the B-DaWorld where its inhabitants are humans, anthropomorphic animals, and robots. Using the legendary B-Daman, Yamato enters the Winners tournament organized by a group (the JBA in the Japanese version and the IBA (International B-Daman Association) in English version) to become the B-DaChampion. However, he also ends up in fights against the Shadow Alliance.
