As one day numerous playing cards fell from the sky the twelve year old Dan and his friends were quite surprised. With the collected cards the friends promtly invented an exciting fighting game, where the mythical creatures depicted on the cards had to fight against each other. But things quickly got much more serious, as the monsters suddenly awoke to life. The location of the great battle between the so-called Bakugan is the parallel universe of Vestroia. Dan and his dragon-like Bakugan Guardian Pyrus Drago are the leader of the "Bakugan Battle Brawlers".