Ichika Asagiri is a 42-year-old housewife. When her son was still a teenager, she divorced her husband on a momentary impulse and ended up sleeping with her son. She continues to hide this secret from her husband. Since then, however, her son has increasingly demanded sex, and she no longer has the strength to resist. She doesn't fully understand her own feelings anymore. How long will this incestuous relationship continue? Will the day come when her husband finds out?