A high school girl's younger sister, Sumire, is left alone with her brother. Taking advantage of their parents' absence, she carelessly throws off her clothes and wanders around the house in sloppy loungewear, braless with erect nipples clearly visible, and pubic hair peeking out from her shorts. The brother, aroused by this unconscious seduction, paws at Sumire's sleeping body and even becomes jealous of her date, forcing her to perform oral sex. The answer that the sister gives to such a brother who cannot be honest with himself is、、、
