In Tokyo, I suddenly started living with my sister (Kokoro) in my cramped apartment. Before I knew it, Kokoro's breasts had grown enormous, and she was always walking around the house half-naked, leaving me nowhere to look! I couldn't take it anymore and forced myself on her, ejaculating inside... But that night, 'I've been feeling frustrated too...' this time, Kokoro initiated sex with internal ejaculation!? We have a secret relationship that we can never tell our parents about...
