Haruka doesn't have to know Hans is secretly a jerk to hate Hans. Haruka will hate Hans for being smooth, and good with the ladies, and generally GOD WHAT AN INCREDIBLY CLOYING GUY HOW CAN ANYONE STAND THAT (then she turns around and calls a cute girl "kitten"). There's a double standard here.

Which will only be further pounded in if he attempts to hit on her, so by all means, go for it!