Ayumi, the daughter-in-law of a wealthy landowning family, lived a happy life after marrying the heir. However, her husband developed a gambling addiction and suddenly passed away, causing the family business to collapse. As a result, Ayumi was left with an enormous debt and forced to take responsibility. Now a young widow, she falls into a state of shock and emotional numbness. Outwardly composed and modest in appearance, she secretly harbors a deeply repressed, lustful nature. Gradually, her hidden masochistic desires begin to awaken as a debt collector sexually dominates and trains her, leading her down a path of intense BDSM, tight bondage, and hardcore submission—ushering in a new, depraved chapter of her life.