Secret (2007)

Ye Xianglun (played by Jay Chou) is a transfer student from Tamkang Art High School, and his father (played by Anthony Wong) is a teacher in the school. This day, his classmate Qingyi (played by Zeng Kaixuan) took him to visit the school, and then he went to the school's old piano room alone. He played a good piece of music himself and was attracted by a piano piece coming from somewhere...