Kyoko, who had been troubled by her sexless marriage, one evening noticed light leaking from her son's room and opened the door. There she saw her son deeply engrossed in masturbation… Her son, whom she hadn't seen for a while, had grown into a full adult, and his erect penis made Kyoko involuntarily swallow her saliva. Since that incident, Kyoko couldn't stop thinking about her son's erection, making it hard for her to do housework. Eventually, she stealthily reached her hand towards her son's crotch…
