Kotonetchan, a usually serious girl, has been secretly troubled because she can't keep up with her classmates' discussions about sex. One day, she mustered the courage to visit her PE teacher's home on a day off to learn about sex. However, that teacher is a pure lecher who goes to brothels every week. Initially, he tried to get rid of Kotonetchan because he was going to a brothel, but he took advantage of her troubles and gradually began to manipulate her body. Kotonetchan, taking the teacher's words at face value, gradually had both her body and mind controlled...
