Yumi had been living an awkward life with her stepson Kenji. The reason for this was Yumi's plump body and big breasts! Every time Kenji saw Yumi, he got aroused, and he would masturbate to Yumi as a stimulant to satisfy his sexual desire. However, Yumi herself finally saw him masturbating. Instead of scolding him for being depraved, Yumi felt sorry for Kenji, who was still a virgin and had never been with a woman, and unexpectedly suggested a round of sex, saying, "It's okay if you just rub it."