When he was a child, his unintentional promise tied the girl's heart for life. From separation to reunion, she learned that he was married, but the girl concealed it and was willing to be taken care of by him even though she was sick. Despite his sarcasm, she still stayed close to him regardless of her own safety. And he didn't know that everything was actually carefully arranged by the girl, just to be close to him and see him. Even if the girl knew that she helped the boy fulfill the promise he made to her in the end, she still forgave him because she loved him???