On the day my parents were away at a memorial service, I was alone with my sister, who was about to move. Seeing my sister, who was good at studying and cute, and the pride of my family, in a defenseless state... I couldn't resist my desire and ended up forcibly raping her. Then my sister told me that she might actually have a stronger sexual desire than other people. From then on, I had sex with my sister over and over again until the day we left home to move... This is the record of that day.