Yumi, who had been living in an awkward relationship with her adopted son Kenji. The cause was Yumi's plump body and large breasts! Every time Kenji saw Yumi, he would become aroused and spend his days relieving his sexual desire through masturbation, using Yumi as his 'prey'. However, Yumi eventually caught Kenji masturbating. Instead of being angry that he was perverted, Yumi felt sorry for Kenji, who was still a virgin and inexperienced with women, and unexpectedly proposed 'if it's just rubbing, it's okay'...
