Hiroshi and Yuka have known each other for a while, and they often visit his house. Eri is Yuka's mother, she raised Yuka alone since childhood. Unmarried, Eri has not dated for a long time. When she saw her daughter happy with her lover, she felt jealous. Since he was a student, Hiroshi has worked part-time as a porter, helping him have a strong body. The thorns impressed her body, so she did a lot of wrong … that is seducing her daughter's boyfriend! Hiroshi also secretly admired Eri's body, so when she teased him, he quickly admitted it and started a bad relationship …