My older sister Sumire suddenly returned to her hometown after breaking up with her boyfriend who she was supposed to be living with. She's selfish and self-centered, but she's very charming. I felt nostalgic seeing her like that. When I went to call my older sister, who was relaxing in her old room, she was masturbating, kneading her nipples. I heard my sister's moans, which I'd never heard before. My dick got hard. She found out that I was peeping... From that day on, I helped my nipple-crazed sister with her sexual needs, and spent the summer indulging in incest with her, letting me fuck her dick.