All i have is a little on one of mine. Leo is an art forger. He sells fake art to Crazy Redd, who then sells it.
To redeem himself Leo purchases the genuine art from Crazy Redd to donate to the museum.
Luna is also an artist, but so far I have not set up a studio for her. She will not be an art forger. Just a regular artist.
My other characters have even less backstory than this.
Some of them
Bethany (My Character) - 12%
Victoria - 0%
Soleil - 5%
Coach - 25%
Poncho - 15%
Twiggy - 8% (I used to think She was a guy 0.0 )
Benjamin - 0%
Gala - 10%
Shari - 95% (She is my fave lol!)
Savannah - 29%
I Like doing it a character at a time, Shari to me has done the most in my game to improve her personality ^_^
None of my characters have stories specifically created with Animal Crossing. My mayor character in Mabure, Avril, doesn't have any story behind her beyond the fact I named her the first thing I thought of that I thought was pretty.
My other three characters (Nagako, Rosaline, and Danielle) I have are named after characters from stories I'm writing, and in fact I often learn a thing or two about those characters from playing as their AC counterparts. Granted, this isn't something unique to Animal Crossing; if I have the chance to name a PC, I always name him/her after one of my original characters.