Kyoko lives with her husband and his father, Tetsuo, who lost his wife and deeply envies his son's happy marriage. Kyoko's voluptuous body stirs up long-repressed lust within the elderly man, and his desire grows uncontrollable. One day, when her husband leaves town for business, leaving them alone together, Tetsuo finally reaches his breaking point. In a shocking turn of events, he gives in to his urges and assaults her.