The smell of my sister-in-law's sweat

The Otowa couple returned to their husband's parents' home in Tokyo. Her brother-in-law, Yusuke, who is busy caring for his father, Shigeo, and lives an unfeminine life, is captivated by Reiko's sex appeal. Yusuke smells Reiko's underwear, which has been taken off in the changing basket. The female odor emitted from a mature woman's body destroys Yusuke's rationality and awakens his reproductive instinct. The lewd scent of the step-sister and brother-in-law having sex intensely while covered in each other's sweat and body fluids permeates deep into the tatami...