Well, I think I already know the answer to my own question but I'll ask anyway, At the end of KH we see Kairi go to back to the Secret Place and she sees the drawing of Sora and herself which Sora "edited" by making him give a poupu fruit to Kairi. Kairi draws her giving the poupu to Sora. Is this what connects them to one another?? (The answer is probably no:23