Masae, a married woman whose relationship with her husband has grown distant and whose sexual desires remain unfulfilled, finds herself increasingly frustrated. One night, noticing her son still awake late, she enters his room to scold him—only to discover him frantically pleasuring himself. The sight of her son's thick, erect penis, which she hasn't seen in years, involuntarily triggers vivid fantasies, stirring deep longings within her. Unable to suppress her growing desire, she becomes consumed by thoughts of him, eventually giving in and aggressively making a move on her own son, initiating an incestuous encounter.