After experiencing piss drinking play with her husband, housewife Yume gradually becomes interested in abnormal acts. While her husband is away on a business trip overseas, she secretly drinks with her father-in-law, feeling a thrilling excitement from the forbidden act. That night, her father-in-law asks Yume to pee for him. He had secretly watched Yume and her husband's piss drinking sessions, which sparked intense envy within him. Yielding to her father-in-law's loneliness, Yume begins a taboo relationship with him, continuing their secret affair until her husband returns home.