This role-play is performed by adults. A younger sister who ran away from home after getting into a fight with her mother. The cause of the fight was about my sister's new boyfriend...I had mixed feelings about it and decided to stay with him for the night. Siblings sleep on the same futon, having trouble finding a place to look as they watch their younger sister casually change clothes in front of her older brother. There is no way that the older brother is not aware of it and is in agony alone...Until recently, he has been playing with the body of his younger sister, whom he thought was a child, and his growing delusions and jealousy can't be suppressed, so he forgets himself and rapes his younger sister.