Friends would definitely work! Also gives flexibility so we don't have to force friendship or anything.

Hmm you're two suggestions are good and leave a difficult choice. A war thing could be interesting - like maybe or characters are from opposite sides of a war and are thrown together by something and form an unlikely friendship. But maximum ride style, with the characters escaping and just y'know being cool would also be fun.

I like both of those possible rps! Haha