Sora, Riku and Kairi are friends. But of course, there's always something else. We haven't seen enaugh evidence to support any romance going on here. Maybe only strong friendship. Although, personally, I would like to see Riku and Kairi come together as a couple. What do you think?
But I think that's just my weird KH pairing XD (Although others like it too >.>)
So... Sora/Kairi, but... I dislike Kairi so much 

Glomping him in KH2, etc xDD)
Sora was scared for his friend, and Kairi only cared about getting her lucky charm back 

