Married woman "Sari" lies to her husband and goes on a hot spring trip with her lover, "Eiji." Though anxious about getting caught, she gives in to passion and instinct, diving into intense and passionate sex. Surrounded by fiery lovemaking unlike anything she's experienced with her husband, she is penetrated by his powerful cock from morning to night. Driven by desire and forgetting her love for her husband, she spends three forbidden days indulging in secret pleasure with no one the wiser.