@Beregorn It was implied by another comment in a previous chapter that the reason why she always got second place was because she was both a commoner and a woman, whereas he was a noble and a man. The male bias aside, it was suggested the academy couldn't afford a commoner to be above a noble if they both get perfect marks or risk taking a hit to their reputation and potentially lose funding from nobility, or at the very least they couldn't afford a commoner to be first. At least one noble had to be in first place even if the rest of the top ten ends up being commoners. From what I remember both she and Lockmann basically got perfect scores all the time(with some exceptions I'm sure), and there were several times where teachers, students, and even Lockmann himself thought she deserved first place.
@helloharuuu Some people are oblivious regardless of gender. Just depends on how doubtful and cynical the person is, which isn't necessarily a bad thing. The embarrassment of assuming they love you and acting on that assumption, only to find out you were wrong in the worst possible way(like asking in front of their friends and being laughed at for being wrong), is enough of a deterrent for people to avoid confronting someone about how they feel. I've never had such a bad experience but I've seen it a lot in manga, and while manga is usually fictional, fiction is typically based on reality and things like this likely do happen from time to time.
For me, I'd be in the same boat where the person would have to tell me straight to my face that they loved me romantically or I probably wouldn't get it, although I like to think I would at least be able to notice the hints. After noticing the hints I'd then decide whether or not I wanted to ask them how they felt about me if I thought it necessary(for instance if I became impatient) or ignore the hints if I wasn't interested.