Hon Sam is main villain of Hong Kong film Infernal Affairs.  He is Ming's mentor and a triad boss. Hon Sam had a
Hom sam
wife named Mary who was killed by Rival gang Ngais whose half brother was Chan and he loves his wife very much. one of them was Chan has become an undercover agent reporting only to Wong about Hom's crimes and Hom was fatherly figure to Lau Kin-ming whom unaware that he was indriectly responsible for his wife's death by senting her to Ngai clan. Hon sends his gang members to Police adcamdcy in order bring secrets of police and Wong and his team arrested Hom when Chan send tiff off from fractured arm 

In the American remake, the Departed, the character is recast as an Irish-American gangster named Frank Costello.