Life may be unfair but the afterlife is even crueler. Love cant be planned. It happened naturally. When two supernatural beings of the after life falls inlove, things get complicated. Even worst if its an angel and a demon. Why? Because it's between heaven and hell. 

Kim Nayoung is an angel. She's kind hearted and caring. Because of her good deeds, she went to heaven after she died just recently and now she is put to a test to see if she really deserves to be in heaven. On the other hand, Bang Yongguk is a demon. The worst kind of demon that lives at the deepest and hottest part of hell. He's gone out for a mission to corrupt an innocent mind of a human and this is where the two creatures meet.

Last but not least is Kang Soyeon. She is nothing but a normal human being. The human whom Bang Yongguk is supposed to corrupt and for Kim Nayoung to protect. What will happen between these three?