Bakugan Battle Brawlers begins with Danma Kuusou, a boy who invented the game Bakugan with his friend Shun Kazami after mysterious and seemingly random cards fell out of the sky. Together with their other friends, they form a team called the "Bakugan Battle Brawlers" in order to play this new game together. But unknown to these young friends, Bakugan is much more than a simple past time. Their game accidently sucks them into an alternate dimension called Vestroia, the home ground of Bakugan.