The Melancholy of Haruhi Suzumiya (light novel)

Meet Haruhi - a cute, determined girl, starting high school in a city where nothing exciting happens and absolutely no one understands her. Meet Kyon - the sarcastic guy who sits behind Haruhi in homeroom and the only boy Haruhi has ever opened up to. His fate is now tied to hers. Meet the S. O. S. Brigade - an after-school club organized by Haruhi with a mission to seek out the extraordinary. Oh, and their second mission? Keeping Haruhi happy . . . because even though she doesn't know it, Haruhi has the power to destroy the universe. Seriously.