How many movies have Christopher Sun and Justin Cheung Kin-Sing collaborated on?

They have worked on 4 movies together! Their first movie together was 3-D Sex and Zen: Extreme Ecstasy (2011) while their highest rated movie together was Imprisoned: Survival Guide for Rich and Prodigal (2015). They have not worked together since Imprisoned: There Is No Escape From Fate (2023). They are most known for their drama films together.