sumire kuramoto, who was supposed to be living together, suddenly returned home after breaking up with her boyfriend. she is spoiled and selfish, but she has charm. i felt nostalgic seeing her like that. when i went to call my sister, who was relaxing in her old room, my sister was enjoying masturbating by rubbing her own nipples. i had never seen my sister's moans before. my dick got hard. i was caught peeking... from that day on, i helped my nipple-obsessed sister with her sexual needs, and i was able to fuck her, indulging in incestuous sex for a summer.