Sinopsis: Lun (Jay Chou) lives with his father, Chiu (Anthony Wong), the music teacher of Tamkang Secondary School. Both of them are very good at music and piano.

On the first day of Tamkang Secondary School, Lun walks through the campus with his classmates, a mysterious piano solo draws his attention. He follows the song and finds that an ethereal girl is playing piano in the old music room.

The piano girl is Yu (Guey Lun-Mei), one of Lun's classmates. She is always late for school and hence sits next to Lun at the back row. The two become intimate friends and spend a lot of time together. “What's the melody you played the first day we met?” asked Lun, “That's my secret.” Yu whispered in his ear.