Hajime was raised as an overprotected only son in a wealthy family. His mother, Nozomi, was worried about her son's unreliable side, but one day, he tells her he's bringing his girlfriend home. "Since he chose her, she must be a kind girl," Nozomi thinks, welcoming her warmly. However, the girlfriend, Yukine, is beyond anything she imagined. Her appearance and behavior can't be dismissed as just "modern youth"... and then, she snaps, "Auntie, what kind of education are you giving your son?" From there, the entire family begins to be sexually dominated by the son's delinquent girlfriend...
