Reika becomes the sex slave of one of her former classmates, Niimi-kun. She is now tasked with relieving his sexual tension, so he can study better. During their time in school Niimi-kun will have to adapt to his senpai becoming his new “study” partner, find out why and how she became a dropout and deal with the jealousy of his peers, especially Reika’s ex-boyfriend, Shiroshima.