Shiori Yamate returns home during a long holiday to visit her father-in-law, who has recently started living alone. Their relationship feels awkward after not seeing each other for some time. The two once shared a brief, secret affair born out of loneliness—a single mistake neither can easily forget. Her marriage has also grown slightly strained. One evening, while her husband is out drinking, Shiori finds herself alone with her father-in-law for dinner. That night, he makes a move on her...