Yumi's husband is currently away on a business trip, so she has asked her brother-in-law to stay over and keep her company while she minds the house. However, the brother-in-law has ulterior motives and begins playing various mischievous tricks on the unsuspecting Yumi. His intentions go beyond mere playfulness—he aims to deepen his relationship with her. As their bond grows stronger, the situation takes an unexpected turn, leading to an intense and unmissable development.