Myungsoo and Sungmi are friend since high school . What Myungsoo don't know that Sungmi had a crush on him. And its break Sungmi heart when he told her that he love someone. And it is more worst when she knew that she had a heart diseases. She wanted to tell Myungsoo herself but she just can't face him. So the last letter will explain everything.

Myungsoo reaction after Sungmi last letter.. *im at description*