Ice Cream bound friendship. That's why Roxas was so broken up about who else he'd eat ice cream with when Xion went back to Sora. Axel mentions earlier in the game how they're best friends because they eat ice cream together.
I think Roxas was one of my most favorite characters in this, because most the time he was just trying to figure out who in the heck he 'was'. He just wanted to live a simple life with friends and stuff and just be normal. But because of his other half, people kept dragging him back into all these things like the Organization, and just tons of dealings with Ditz, though, to his credit, he never once have up, because it was the only way he could thing of to find himself.