Parents who married with children. Her father had a son and her mother had a daughter, and they became brother-in-law and sister-in-law. One day, her sister-in-law Mio loses her underwear. She happens to peek into her step-brother's room and is confronted by her step-brother masturbating in her lost underwear. I got into a fight to get her underwear back, and with that momentum, I was raped... At that time, I was mistakenly inserted into my anal...
