Myungsoo Kim: A very handsome junior student who attends Woolim University, majors in photography. His girlfriend(you) died in a car crash and blames himself for everything. Just when he reached the bottom of his life, he starts noticing signs that might be left by his girlfriend ....

Hyora Song(you): a beautiful junior student who attends Woollim University, majors in music, died in a car crash. Her spirit haunts her beloved boyfriend who is in more agony than ever, and hopes to restore his confidence in life.

Other Charcters: 

Members of Infinite

Taeyeon Kim(Myungsoo's sister)