The story was about high school student Ye, who studied in the school his father taught. Ye's piano skill was above others.On the first day of school, while walking around the piano rooms, he heard an unknown and beautiful melody, played by Lu. From then on, the two were always together.However, Lu seemed mysterious and when Ye tried to get to know her more, she always brushed off his questions by saying that it was a secret.There was a misunderstanding between the two of them, and subsequently Lu never came to school anymore. Ye was heartbroken.But the more he tried to find out, he realized that things were not as they seemed.