It started out as a game… or at least as a competition. Yukio Mimura comes from a well-off family, and has never needed anything. Kind and well-mannered, he obediently carries out his parents’ last will: to find his lost cousin and settle him in the family mansion, which he does. But brother Hayato turns out to have his own plans for the mansion, his future, and especially for Yukio’s girlfriend, Reiki… Unaware of his family’s sado-masochistic past, Yukio is forced to enter a sexual competition to avoid exposing his family secrets to the public. In this contest, the first one who manages to tame her gets the family mansion and the money. Reika, who finds herself in the middle of this perverted ritual between her boyfriend and his sadistic brother, is forced to choose a winner: either the one who enslaved her, or the one…who loves her.