Three years after getting married, Ria Kashii is living a happy life with her husband. One day, the doorbell rang just as the couple was feeling satisfied. Ria went outside to check the camera and saw the man who had been her lover years ago. She was shocked to see his disgusting face again, but when her husband asked who it was, she pretended to mistake the house. Then, when Ria's husband went to work, he appeared again; he sweet-talked Ria into opening the door, which led to her and her husband's fateful days...