Five years into her marriage, Rika and her husband have a relationship more like best friends. She kept telling herself she was happy, but deep down, she harbored a loneliness as a woman. Then one day, her husband's older brother, Yuzuru, came to Tokyo on a business trip and stayed at their home. Even though he was family, having another man in the house made Rika's starved heart and body impossible to restrain. One night, she went to Yuzuru's bedroom, secretly straddled her brother-in-law, and whispered, "Don't move... I'm the only one doing something wrong," as she began to slide her hips...