Eri lives alone with her only son, as her husband is working overseas for a long time. She disciplines her son strictly, hoping that he will grow into a respectable adult like her husband, but the results are not coming, and she is just getting more and more stressed. Eri herself is also sexless and frustrated... She can't help but masturbate, and is seen by her son's friend, Kenichi. Seeing his erect penis, Eri's suppressed sexual desire explodes. While scolding him for peeking, she firmly grasps his erect penis and begins to stroke it violently...