I wonder when it started. My sister's panties, which are so long yet so defenseless, caught my eye and I kept taking sneak peeks at them. Gradually, her panty shots got me more and more excited, until finally I couldn't stand it anymore. When I was alone with my sister in a room, I rubbed her thighs, stared at the warm panties at the base of her thighs, sniffed them, and took them off. She started sucking on her vagina deep inside her panties, and then my dick... This is the first full-scale drama that the Sayaka Otohaku has ever attempted.