Tatsuo went to visit Shunka, his girlfriend. At that time, he happened to meet her mother 'Murasaki' and became aroused. Murasaki was also sexless with her husband and became aroused upon seeing a young man, leading her to masturbate. Tatsuo, having witnessed the scene, couldn't stop thinking about Murasaki. Later, unable to hold back, Tatsuo pressured Murasaki for a relationship. Despite saying it was wrong, Murasaki betrayed her daughter and sought his penis.
