Born in the U.S. and relocated to Hong Kong, On was approached by China Star founder Charles Heung and world renowned filmmaker Tsui Hark to take over the role of one of Jet Li's famous movie characters, Black Mask, in Black Mask 2: City of Masks (2002). Andy went to the Shaolin Temple to train for a month in stretching and martial arts for the role. Despite the poor reviews and bad box office sales, Andy has continued to act and, in fact, improve in not only martial arts but acting as well. He was nominated for the Best New Actor Award for his role in Siu nin a Fu (2003) (aka Star Runner) and shared the screen with the man who influenced him, Jackie Chan, in New Police Story.