Dan Kuso's life changed one day when 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 accidentally dragged into fighting into the fate of Vestroia (the home dimension of the Bakugan) 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 almighty power and absolute control over Earth and Vestroia.
