A boy attempts suicide, but with the attempt, he receives amnesia. When he arrives at the home, making friends is an odd experience.

"They called us 'Zodiacs', named from our constellation mothers, the stars. We may talk, look, and act like a human but I can assure you, we aren't one of them. In fact, we are warriors born to fallen. Our destiny was to stay alive until the time comes where we would have to sacrifice ourselves in order for them to survive."