The married woman "Rin" lives with her brother-in-law, but her patience has reached its limit with his terrible behavior. One day, her brother-in-law asks her to wear boots, and Rin agrees, thinking it's no big deal. However, her aroused brother-in-law takes advantage of her and forces himself on her. From that day on, she's caught in a cycle of guilt and pleasure! She engages in forbidden adultery with her once-hated brother-in-law, a secret she can't share with her husband who's busy fucking her every day.