Eye for an Eye.

A high school girl, Yu Shan, has long harbored a crush on her classmate, Pin Lun. She finds satisfaction in stealing his small belongings, as this gives her a sense of possession. She knows Pin Lun's weekly schedule, including when he practices piano. Once, Yu Shan sneaked into the music classroom ahead of time, and reveled in the pleasure of accompanying Pin Lun from a close distance as he played the piano.