Hisae, a 40-year-old wife, receives almost no affection from her husband and grows increasingly frustrated with her unfulfilled desires. One day, in an extreme attempt to relieve her stress, she crosses a forbidden line by making a move on her own son. She feels intense sexual arousal from his reactions, awakening her deep-seated female masochist tendencies and intensifying her emotions and lust. As her relationship with her son takes on a new, twisted form, Hisae's inner desires begin to spiral out of control.