This might sound odd and may not even get the chance to happen for awhile, but I feel like both of these kids need to let loose a little. Finn and Shiro have a lot in common in the "too young for this weight of the world shit" category.

I was planning for Finn to travel around Vaikuntha and have a little bit of fun. Visit chocobos, eat weird things, get drunk at least once, etc. He'd be down for meeting up with a buddy somewhere if Shiro is willing/has the time.