Maika Asai's peaceful life comes to an end as she faces a dire situation pushing her toward divorce. Her husband, Kenichi, is having an affair and has also done something terrible to their son, Toshiyuki. Overwhelmed by the fear of losing even her beloved son, Maika's mind begins to unravel. Trapped in despair, she is forced to make an extreme decision—to protect herself and her child. Buried deep within her psyche, a hidden desire begins to emerge, guiding her toward an inevitable act of incest.