Right from the moment she was born, Im Sooha could see numbers floating above people's heads. It isn't until she witnesses the death of her parents that she realizes what those numbers mean. Sooha can see just how long a person is going to live by the amount of numbers left on the personal clocks on top of people's heads.

          After such a traumaticizing experience with her parents, Sooha does not dare to interact with people for fear of losing them and not being able to do anything about it. It isn't until she befriends Park Chanyeol, a boy who's days of living continue to drastically decrease that she starts to realize just how helpful--and life-saving-- her ability is.