One day, when Natsumi was putting away her son Hiroshi's futon after he had gone to school, she accidentally discovered an adult DVD underneath it. When she questioned her son about the situation, she was taken aback by the anger of the usually mild-mannered Hiroshi. While lying on the sofa, she woke up when she noticed her son peering up her skirt. When she asked him about his strange behavior lately, he said he had begun to become interested in women's genitalia. "Since his father is gone, I have to be strict with him," Natsumi said, as she used her own body to teach her son sex education, but her son's demands escalate...