A young college student named Saji, living alone, meets a married woman named Aina at a local izakaya. They hit it off and continue their conversation at Saji's home until dawn. Despite knowing their relationship was forbidden, they grow closer over time. One day, Saji gives Aina his house key, which leads her to start visiting him while her husband is away on business trips. To cope with the loneliness, she spends intimate moments with Saji, indulging in their passionate affair...