The two spent a good part of the day wandering around the city, seeing things, catching up.
Kairi didn't dislike Riku, she just...was a heartbroken girl. She confessed to Sora over their lunch at a quiet coffee shop, that she really had loved him, and she still did. That sometimes she wished that she hadn't let him go. Except...she couldn't really regret it, because she saw how happy Sora was. And she proceeded to tease him about Riku as much as possible. It was a bit awkward for them both, this conversation. There were a lot of things for Riku and him to get through, but he wanted to get through them so badly, and Sora knew he was falling for Riku. It was hard to tell Kairi that, but he had to tell someone.
The two lost track of time, and before he thought of inviting Kairi over for dinner, it was already dark. He texted Riku that he'd be home soon, and after walking around a park and talking in her car about his parents, his situation, how he felt about it, Kairi dropped him off at Riku's house.
Sora felt completely drained. He had been trying so hard the last few days to forget about what he was going through for the sake of not bugging Riku. Sniffling, eyes red from crying (something he also hadn't done enough, and was reluctant to do in front of Riku) he came in the door quietly, hoping the family was still at dinner. He just wanted to lock himself in the guest bedroom and sob for a while.