Takayuki, Hina's husband, suddenly announces a three-day business trip, while her unemployed, reclusive brother-in-law decides to move to Tokyo for job hunting. As a result, Hina is left alone with her brother-in-law for three days and two nights. Though she is bright, beautiful, and virtuous, she gradually falls into one clever trap after another set by her brother-in-law. Succumbing to pleasure step by step, she transforms into a lustful, desire-driven married woman. These days mark a new beginning and a major turning point in her life, profoundly shaking her heart and desires.