Roxas first saw Kairi in his dreams and memories. Naminé was reconstructing Sora's memories and this was affecting Roxas. Roxas put a seashell up to his ear and saw Kairi in a memory. He also sees a memory of Kairi on Destiny Islands and notices that she is similar in appearance to Xion. It turns out that Xion looks like Kairi to Roxas because she is representing Sora's strongest memory.
Roxas eventually had his memories wiped and was staying in a simulated version of Twilight Town. He had dreams of Sora's memories as a result of Naminé's work and saw Kairi a lot in these dreams. It took a while for Roxas to completely remember Kairi's name but he eventually remembered. Roxas fell off of the clock tower and connected to Kairi telepathically. He initially mistook her for Naminé but remembered her and mentioned that she was girl that "he" likes. Kairi begged for his name as she could not remember and Sora eventually talked to her through Roxas and gave her a hint about his name.
RokuKai has a small amount of popularity in the Kingdom Hearts fandom. It is not as popular as SoKai or RokuNami. This ship is mainly based on the fact that the two had a brief telepathic connection. Since Sora and Roxas and Kairi and Naminé are two halves to the same whole, some fans feel that they can be shipped interchangeably. RokuKai is sometimes shipped along with SoNami.
- Roxas allowed Sora to contact Kairi telepathically and remember is name.