(my theroy)
Since Kairi is a princess of heart she is pure light. Put when Sora used Riku's Keyblade it release all the princess hearts with a bit of darkness in them. Since in KH COM it was said that Naimine was a witch they called her. She was like a person who had the power to mess up ppls memories. So the organization used her to use her powers to mess up sora's memories so that she was the one he would remember not Kairi. But in the end she tells him the truth that it isn't her that he is looking for and Kairi's charm was changed into a charm that naimine made, but sora still had Kairi's charm so i think thats what connects Kairi and Naimine. Then in KH2, Roxas had met Naimine which meant that they were connected. Then Roxas Speaks to Kairi when he is falling i think he calls her *Naimine* but then she corrects him. Thats how i think Kairi and Naime r connected