Today's top could be tomorrow's bottom when playing the caste game! School is hard enough as it is, but when students are forced to play a cutthroat game to determine their social ranks--and subsequent treatment--all bets are off. Atsumu, a regular target of the school bullies, has had a rough life. But his luck changes when Kuze, the classmate he idolizes, helps him out during the caste game by giving him his jack card. Despite his reservations about Kuze's true intentions, Atsumu can't help but lose himself in the pleasures Kuze gives him. But will those pleasures come at a cost?