nagisa, a girl in her growth spurt. One day, she enters her brother's room and finds a forgotten porn magazine... "Brother, do you like girls' breasts?" Nagisa shows her breasts to her brother who has returned to the room. Her innocent act causes her brother's reason to collapse. The perverted brother thoroughly caresses the body of his innocent, weak-willed sister. This is a secret record of a brother and sister growing up together...
