Cree Raft and Per Minec have been friends since infancy. As toddlers, they looked very similar, but they grew into two very differently looking children. They are not related.
At story's start, Cree and Per are 8 years old, living on Three in the Cups System, on the same street.
Cree is still very small, much smaller than all his classmates, but short tempered and quick to anger. He also is very sensitive about his size.
Per, on the other hand, hit his growth spurt early and is tall for his age. He also is unusually broad-shouldered, which gives him extra strength for his age. He is bookish and quiet, though not afraid to wade into a fight to rescue Cree. Per is also the only person who can tease Cree about his size without rebuke.