A Gentle Response That Comes Against the Light

Find a Modern Romance Novel in Which the Hero Becomes a Bodyguard in Order to Repay a Favor.

I'm looking for a modern romance novel. The content is probably about the male protagonist agreeing to be the heroine's father's bodyguard for a while in order to repay a favor. It's similar to Enemies. I can't find it now. Anyone who knows can tell me the title of the book?