I am a big fan of RikuxSora, and think they're destinied (spelling?) to be together. The fact that they're much more interesting than Kairi helps a lot. Really, I can't see Riku showing any real interest in Kairi at all, only squares half hints about Sora and Kairi. And my mind deletes any signs of Sora liking Kairi. But really, in KHII, the reunion between the trio. Sora's reaction towards Kairi was a real happy joy "Suck on that B*tch!!" moment. And then he came to Riku, who didn't even look like himself, and he was all emotional and crying on his knees. It's like, Sora and Kairi get the sap-moments which doesn't mean anything, and Riku and Sora the awesomeness with real emotion xD And to Sora's character, he isn't all sunshine. He's actually almost cool in KHII, between the happiness and dumbness. I guess Square needed an all through light person, and there for made Kairi. At least she's brave, or else she would have been a total failure. If people want darkness and angst, I think they should play Final fantasy. That's sounds a little *****y, but think about it. Woudn't the games become a little to similiar if Kingdom hearts went on to angst? Kingdom Hearts for those who want happy endings, and Final fantasy to those who want angst and beauty. Even though Kingdom hearts isn't all sunshine, it still holds the light.
