Due to divorce, Dai's new mother became [Ruka]. However, [Ruka] is a studious mother who forces Dai to study every day. Tired of this, Dai consults with his classmate, the delinquent Masa... One day, Masa lies, saying 'Dai keeps making me cheat.' Shocked, to prevent the school from finding out and to protect Dai, there's no choice but to listen to what Masa says, leading to having his breasts groped and even being forced into sex... Dai, who had secretly filmed this as evidence, blackmails his stepmother for revenge!
