serious/It's not a love story, as such, it's about two people trying to make sense of the world in which they live in.
Kyon is a sarcastic, droll bastard who sees everything as 'bothersome', nothing interesting happens, it's the same old thing day after fucking day.
Haruhi is a restless, over active girl who sees the world as boring, hoping to make a change, because nothing interesting happens in it.
Haruhi meets Kyon, and she realizes, there may be someone like her out there, after all.
So she ropes Kyon into all these things, much to his discontent, but in the finale, he reaches a conclusion. He acknowledges Haruhi. The kiss wasn't because he was IN RABURABU with Haruhi, but an act to show he recognized her. There's no denying what Haruhi feels is love for Kyon, but Kyon doesn't feel anything as such for her, at this point. Subconsciously, he probably does like her, even a little bit, but refuses to admit, instead crushing on Moe Mikuru, because let's face it, a crazy, hormonal girl, or a moe blob?
So no. It's not a love story.