How many movies have Johnnie To Kei-Fung and Shirley Lau Yim-Ngo collaborated on?

They have worked on 4 movies together! Their first movie together was Fulltime Killer (2001) while their highest rated movie together was Septet: The Story of Hong Kong (2022). They have not worked together since Septet: The Story of Hong Kong (2022). They are most known for their crime films together.