He's My Bodyguard

Sena hates her step-father, but when a group of men storm into an anniversary party, they kidnap few and kill most, all while she's in the bathroom. Witnessing only a few minutes, she passes out from fear. When Sena wakes up, she finds out her mother was one of the many who disappeared and is left with the man she hates most, her little sister, and her own personal, hot bodyguard.