Sayoko is a kind and good-natured housewife. She has not had sex with her husband for the past few years. As a mother, she has entered the lustful phase of her life, and it is her daily routine to masturbate during the day while her only son is at school. One day, her son's classmate sees her doing so and discovers her weakness. Using her secret that she doesn't want anyone to know, she becomes the sex slave of her sexually ravenous classmates... Their demands escalate. Finally, she is forced to take an outrageous action!