It was a holiday that should have been no different from any other. On his way home, Asahi notices a notebook lying on the road. "Whoever dropped it is in trouble..." He picks it up and goes to deliver it to the address written on it, and from that moment on, Asahi's life begins to go awry. He never imagined that Nanami, the mother of Nozomi, who had found the notebook, would draw Asahi into a "forbidden" world that only women can enter...