A serious girl of her age, Riena, was troubled because she couldn't keep up with her classmates' sexual topics and couldn't talk to anyone. One day, she visited her teacher's home on a holiday to ask her homeroom teacher to teach her about sex. However, the teacher is a purely erotic teacher who goes to a sex club every Sunday, and was trying to get rid of a student who came to her house to go to the sex service she had reserved, but she was so persistent that she was curiosity. Taking advantage of her, she plays with her body, which is still in the process of development.
