I know for TS2, there's a lot of custom content. I actually have a Kakashi in my game, as well as Sakura (the latter I don't play).
TS3, I'm not sure. I'm sure if you look around for content, you can find it. I'd start with ModTheSims.
You might be able to find Sims others have made as well, by googling Naruto Sims (for three. Be careful or you'll pull up a bunch for two).