Michiru Kita has Shinigami Eyes, which show her a ring around the neck of anyone close to death, darkening as the end comes nearer. The pitch-black rings she spots belong to two classmates who are very much alive, Chika Akatsuki and Shito Tachibana, and the pair turn out to have survived a fatal accident by borrowing their lives from an outfit called Zombie-Loan. Paying that debt means hunting illegal zombies, and Michiru is dragged along because her sight finds the targets.