Mizuro and Nazumi are two twin sisters who are not at all alike. One night, after they had taken their friend Tomo home, the girls heard a scary female scream from somewhere in the Park. The next day, Tomo confessed to Mizuri-Chan that it was her screams and she was raped right in the Park. Later she starts to behave strangely and constantly sexually harasses Misura. Tomo some time later dies without reason, and to investigate the sudden death