Anna Machimura is a full-time housewife living with her college-aged son and her impotent husband. Now in her forties, her libido grows stronger by the day, and her relationship with her husband has become increasingly strained. Meanwhile, she secretly watches her son bringing girls home regularly and indulging in passionate sex, which drives her to frequent masturbation. One day, SakaI, her husband's subordinate, visits their home. Captivated by the man's voluptuous, muscular body, Anna is drawn into a deeply intense affair with him. Her sexual desires, now fully awakened, escalate uncontrollably—until she finally reaches the point of succumbing to her own son...