There all mixed into each other, coexisting and whatnot. Will be using some a preexisting world to use, currently leaning towards Fiore from Fairy Tail or the the map from Naruto. 

In terms of general composition of the populace, nothing concrete but it'll be diverse. Let's say I adapt Naruto's way of distributing the land, then Kirigakure would be the home of not only Mist Shinobi but also Fishmen and could possibly be the location of Marineford. I hope that give you a general idea of the landscape and population.

No character sheets at the moment but I'll try putting one together as a sample. Still contemplating on how I'll be doing the scaling of power. We all know the standard of what is considered strong varies from one series to another. 

Anyway, I'll try fleshing this out a bit more.