Like it's been mentioned before, you can pretty much just think up of any sort of special abilities or techniques or character concept you want and I'd be more than happy to jigsaw the game mechanics around that. The system's flexible, and so am I.
As for the plotline... I like the idea of the protagonists eventually leaving to start their own village or somesuch. And I also like the idea of avoiding the 'featured' villages in the canon. So maybe having it start off in the more obscure villages like Rock, Mist, or even Grass and Waterfall.