This role-play is performed by adults. Natsume, who transferred to Tokyo, was having a fun school life. One day, she is called by her homeroom teacher, Oki, and is warned that her grades have been declining since she got a boyfriend. Natsume is forcibly invited to Oki's house to watch him study, and forced to drink an aphrodisiac. Natsume is raped by Oki in a hazy state of consciousness... Natsume is forced to write an ``exclusive obedience contract'' and falls into Oki's slave...