A Dirty Carnival (2006)

Kim Byung-Doo is a charming low-level gangster creeping up on 30 years of age. His youth rapidly fading, Kim has seemingly been on the cusp of making something of himself for years, his natural charisma making him well respected among his peers while a manipulative boss and string of bad luck has kept him firmly locked into his lowly status. When a wealthy industrialist approaches Kim's boss to eliminate a bothersome criminal prosecutor, Kim sees his long-awaited chance to advance and takes it. But all advancement comes at a cost...