Zombie-Loan

A girl named Michiru Kita can see dark rings around people's necks, indicating how close they are to death. She observes two classmates, Chika Akatsuki and Shito Tachibana, who have completely black rings. When she tries to warn them, she discovers they are already dead, sustained by a contract with Zombie-Loan. As part of their agreement, they must kill zombies. They enlist Michiru's help, using her ability to see death signs in their mission.