From MangaHelpers:
There's a new transfer student in school named Midori, and she is very cold and set apart from everyone. For some reason, though, everyone seems interested in her. One day, Ao witnesses proof that she is a supernatural being, and confirms with her that she is actually a god. He carelessly asks a wish of her, like people have been sending to the popular "god's e-mail" address that's suddenly been going around school, and she grants his wish. Unfortunately, the cost is high. She kills him-- only to bring him back as a shinigami.
Now, Midori informs him that his job is to show up where people are going to kill themselves and die in their place. Ao feels the pain of each death, though, so it's not something he wants to repeat over and over. For that matter, ending a person's single suicide attempt doesn't necessarily mean that he has done anything about the reasons they were willing to take that step. Will Ao find a way to cope with his painful new life?