No. YOU have to make them, as in when the game starts, you get the option to make a new resident and you have to play as them too. They don't just walk around and do their own things lol
Why does everyone make multiple characters? I did that in Wild World and it caused me to confuse everything and only ended up using one character anyways. Plus, I could never know what fish or bugs I needed for the museum because 1 character had some, another had more, and another had a few random ones donated.
Anyways, only the first character is mayor. The other is just a resident. However, you can not play both at the same time, and when you play as one of them, you won't see your other character.
I'm going to make all 4 just to build themed houses, just for show, something more to do, and something for people to explore via wifi or dream suite :3