Sana who has been married for half a year, is living with her husband's father, who is now single after separating from his wife. Her husband is rarely home because of his frequent business trips, so Sana continues to live alone with her father-in-law. One day, Sana witnesses her father-in-law masturbating using her underwear. Perhaps because she is lonely and unable to see her husband, Sana seduces her father-in-law, and they are led into a forbidden relationship...