Sanshiro's chances of having an adventure are slim to none on his tiny island hometown. Until the day when a mysterious stranger invites him to play a game... Without warning, Sanshiro is taken to a reverse universe to play Bakégyamon--a game pitting monsters against monsters, with a twist. Along the way he meets other opponents who have their own reasons for being there. Namely, a wish that is granted to the winner of the game. But how far can Sanshiro get when the monsters he's been paired with are a bunch of little mud balls?!