A serious girl her age, Riena, got into trouble because she couldn't keep up with her classmates' sexual topics and couldn't talk to anyone. One day, I went to my teacher's house on a day off to have my homeroom teacher teach me about sex. However, the teacher was a real porn teacher who went to customs every Sunday, and was trying to get rid of the troublesome students who visited his house to go to the customs he had booked, but he was too stubborn, so he took advantage of her curiosity and toyed with her growing body.