I'm not sure how to describe Haruhi in a way that isn't totally cynical x.x|| I guess basically she believes in aliens and monsters and such and wants to meet them, so she won't talk to anyone who's "human" (aka she's really standoffish and snotty to everyone in her classroom). And so she pulls all these stunts to supposedly get their attention. Though if she were living in the U.S., people would have correctly diagnosed her with attention seeking behavior and sent her to a psychiatrist to talk about whether her parents give her enough attention or not >,< This is demonstrated by a comment that even though she supposedly wants nothing to do with humans, she'll say yes to any guy who asks her out and then dumps them after about a day.