A Love to Kill (2005)

Bokgu, the orphaned son of an abusive mobster, idolizes the older brother who raised him. Believing that famous actress Cha Eunsuk abandoned his brother and caused the attempted suicide that left his brother hospitalized in a coma, Bokgu plots his revenge, landing a job as Eunsuk's bodyguard to try to seduce her and destroy her reputation and career. Bokgu is bound by both guilt and affection to Han Dajung, a childhood friend who pulled him from a fire and saved his life, but was burned and left with permanent scars. He stays with her in a life he despises, as strong-arm man for her loan-shark business. As Bokgu exacts his revenge on Eunsuk, he is torn between his growing feelings for her and his sense of obligation to Dajung, between his duty to avenge his brother and the increasing uncertainty that his revenge is justified. His external actions contrast with his inner turmoil, and finally, he is filled with self-loathing at his revenge's successful result.