Ji Eun has always been a happy person, the kindest of her kind. The positive one that everyone likes but it is about to change in one night, when she learned the truth of herself and met a man. She should have not been there to experience the misery, not by herself. 

He was always cold hearted, life had shown him the truth from the start but deep down inside, he owns human values which he couldn't share. She came in, she was a mistake.