Bai cu shi fu kou cu tou (1979)

After being exploited by a fake kung fu teacher, Ah Tai (John Chang) searches for a real master and ends up meeting a ruthless hit man, Ghost Hands Lo Sum (Hwang Jang Lee). He tricks Ah Tai and sells him off to be a sex slave, but Ah Tai escapes and befriends a real kung fu expert Fan Siu Mung who teaches Tai how to fight so he can avenge all those who wronged him.