A Love to Kill(2005)

Original title: 이 죽일 놈의 사랑

A good-for-nothing K1 fighter begins working as a top celebrity's private bodyguard, with the intent of seducing her and then leaving her to ruins, as an act of avenging his older brother who was left in a coma. Soon, he finds himself falling in love with her, their romance a tragedy in the making.