Based on the erotic game by Bishop.
Yuugo, a physical education teacher at a girls' school, is teased by the students, and is especially bullied by Rikka, a young lady from a wealthy family. The only person who treats him naturally is Sayuki, a transfer student. However, as they become closer, Yuugo begins to have dreams about abusing her. He then remembers that he has the ability to control human bodies, and that Sayuki is the younger sister of a girl he raped in the past. He uses his ability to make the unsuspecting Sayuki kneel, and as the first step in his training and domination, he orders her to serve him in an impossible manner.
(Source: parabook, translated)