Do you know when you are going to die? Michiru Kita does, because she can see a "ring of death" on the necks of people around her—and the darker the ring, the closer they are to death. One day, she notices that two boys in her class, Chika Akatsuki and Shito Tachibana, have completely black rings. Trying to warn them of their impending demise, she discovers their secret: they are already dead, but are kept alive through a contract with Zombie-Loan, a mysterious loan office. Of course, nothing comes without a price, as the boys must hunt down and kill zombies to pay off their debt. And once they learn about Michiru's "Shinigami Eyes," they drag her into their crazy world.