Ayano was living a life where her husband no longer saw her as a woman. In her loneliness, she began a secret affair with a younger man, indulging deeply in her desires. By chance, her son Subaru witnesses one of these trysts. Shaken by his mother's moans, he feels an abnormal excitement stir within him. When her husband returns home drunk and Ayano tends to him, a new, forbidden relationship begins—right before the sleeping husband's eyes.