Cha Joon seems to be incredibly possessive of her, even though he knows that he probably can't be with her. kind of like how he asked her to wait for him, only for him to be late and with another woman (though not a love interest for him) so I can only assume that this is going to be how their relationship plays out until he gets his family life sorted out. And the black haired guy started out as extremely unlikable, though now that we are learning more about him he becomes more likable, while Cha joon seems to be deteriorating though I think he's super cute-