KJ is a biography of a HK musical genius. At the age of 11, KJ won the Best Pianist price and went to Czech to perform with a professional orchestra. Touching on subjects such as the meaning of life, God and the artistic process, the director’s 6-year-conversations with KJ reveal how a young man inspires by his music teacher, Nancy Loo and how he conflicts with his peers and parents. KJ is not about the victory of a genius, but how he learns to be a "human being".

黃家正是一位年僅十七歲的音樂天才。他的父親是一位醫生，因此在物質生活上不餘匱乏。十一歲那年他贏得香港校際音樂節鋼琴組大獎，也獲得去捷克和當地專業樂團合作演出等等的機會。對於這樣的人生他卻開始產生疑問：「為什麼要演奏音樂?」和「人生就只有音樂嗎?」諸如此類的問題在他小小的腦袋中層出不窮...