Yukine who lived away from her parents' house after losing her mother. However, after a long absence, I decided to return to my parents' house where my father-in-law and younger brother were. Even though I met my cute little brother and stroked my chest, I soon discovered the secret of my father-in-law and my younger brother. How bisexual my father-in-law was ... Yukine decides to take off as an older sister because she is a younger brother who is treated as a father-in-law's sexual treatment.