Wrapped in the monotony of daily life, Reiko finds herself emotionally starved as her intimacy with her husband fades into nothingness. One day, Shito, her husband's friend, comes over to repair the bathroom vent. When he exposes himself to her, Reiko is overwhelmed by uncontrollable desire and gives in to temptation, committing an act of infidelity. Using the secret of that incident as leverage, Shito begins treating Reiko as his personal sex toy. A new, twisted relationship forms, pulling her deeper into a world of inner conflict, forbidden pleasure, and relentless seduction.