Boogiepop Series

There is an urban legend that children tell one another about a shinigami that can release people from the pain they may be suffering. This "Angel of Death" has a name—Boogiepop. And the legends are true. Boogiepop is real. When a rash of disappearances involving female students breaks out at Shinyo Academy, the police and faculty assume they just have a bunch of runaways on their hands. Yet Nagi Kirima knows better. Something mysterious and foul is afoot. Is it Boogiepop or something even more sinister...? Source: Seven Seas