/r/Bakugan

Bakugan is a toy battling and collecting game from Spin Master. They are transforming spheres that activate when attached to a magnetic surface. Bakugan (爆丸, Bakugan?) are creatures from an alternate dimension called Vestroia, along with the worlds of Neathia and Gundalia. It is also a game that uses these Bakugan. The kanji for "Bakugan" reads "exploding sphere".