A Bittersweet Life (2005)

Kim Sun-woo is an enforcer and manager for a hotel owned by a cold, calculative crime boss, Kang who assigns Sun-woo to a simple errand while he is away on a business trip; to shadow his young mistress, Hee-soo, for fear that she may be cheating on him with a younger man with the mandate that he must kill them both if he discovers their affair.

Director:

Kim Jee-woon

Stars:

Lee Byung-hun (Sun-woo), Kim Yeong-cheol (Mr. Kang), Shin Min-a (Hee-soo), Kim Roi-ha (Moon-seok), Lee Ki-young (Oh Moo-seong), Hwang Jung-min (Mr. Baek)