Hiroki lives a peaceful life... But one day, a girl, Kotono, and a boy, Kyosuke, suddenly appear in front of him. Hiroki doesn't know what's happened... Mimori, his old friend, tries to call the police, but she can't see them. Though Hiroki and Mimori forget it and go to school, Kotono and Kyosuke follow them and comment on every move they make, even when having sex..? What will happen to Hiroki's school life!?