A Bittersweet Life (2005)

When doing right goes very, very wrong.

1h 59m · Released · TMDB ★ 7.4 (1054)

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

Starring: Lee Byung-hun, Kim Yeong-cheol, Shin Min-a, Kim Roi-ha, Lee Ki-young, Hwang Jung-min