Alright, planned things out a bit more. The main tournament that the story focuses on (at the start, at least) isn't one of the major tournaments, instead more of a qualifier - while there's a decent cash prize for the best Tamers, the real prize is an invitation to a much larger tournament. Still, it's not exactly a small tournament, taking place over about a week's time, in a very large location.
The story would start a few days before the tournament, with the PC tamer(s) just arriving. There's been a few incidents, however, and while that's not terribly uncommon in the Pokegirls world, there's rumors of something sinister going on.
I'll start writing up a main thread.