This is mainly about a girl named Song Ji eun and her best friend Hyousng they were both living tougher and after a few years a killer Kim Himchan finds out that they are living there and he is a killer and he is crazy.He was planning to kill both of them but falls in love with one of them and kills the other best friend.When he kills the friend he makes the other friend watched to make her just like him.After that she is watching out for signs of her friends ghost and for Himchan.After a few years she falls in love with him.

 Who do you think is the Best Friend who dies and the best friend falling in love with the killer.