Season 1
Dan Kuso's life changes one day when strange cards fall out of the sky and he grabs one, which he and his friend Shun use to invent a game they call "Bakugan." With other friends, they formed a group called the "Bakugan Battle Brawlers." They are then accidentally dragged into fighting for the fate of Vestroia (the home dimension of the Bakugans).
Vestroia loses its natural balance and merges with the Earth and many other worlds. A rogue Bakugan called "Naga" has been tempted to capture the power of the Infinity and Silent Cores, which together formed the Perfect Core that balanced Vestroia, but Naga has absorbed too much negative energy and thus has been trapped within the Silent Core, destabilizing Vestroia. Naga now seeks the mighty Infinity Core so that he can complete the all-powerful Perfect Core and have absolute control over the Earth and Vestroia.
Season 2: New Vestroia
Three years have passed by since the Brawlers defeated Naga and bid farewell to the Bakugan. Drago sacrificed his physical body to become the new Perfect Core, uniting the Bakugan's fractured homeworld and forming New Vestroia.
