Akumateki Shoujo

One day, 15-year-old Tanaka Atsuko fell off the roof of a building and died. Although her spirit is disoriented and having a hard time remembering things, she simply does not believe that she would have killed herself. She has little time to ponder this before a business-like demon, Suzuki, shows up on the scene, eager to make a deal for anything the newly dead Atsuko might want. With the dubious help of Suzuki, will Atsuko be able to unravel the events that led to her death and prevent things from getting even worse for the people she's left behind?

(Source: MangaHelpers)