Welcome to PC's FF&W!
Okay, random formality aside, let's get on with the review. I had a few problems with the concepts of your story. For example, when Leaf had used Toxic to clear students I thought that was just a bit too overboard. I mean what's wrong with Christy just shoving her way through? Also, I don't know if you mentioned Leaf's age or not, but Leaf knowing Toxic alone is a bit odd. Toxic is a TM move remember, and the point is Leaf wouldn't learn it naturally. Even more so that it wouldn't be taught it from a girl still in school. And if some Snivy spit poison on my shoes, I'd be pissed and I think I'd try punting it across the auditorium.
Another thing, the buildup for finding out the partners was very very predictable. Actually, the first paragraph was practically screaming Christy and Jake were going to travel together. I mean the narrative only focused on them and how much they liked to hate each other. If you wanted it to be predictable, then I guess you did too much of a good job.
Other than that, there's not much else I can really say. Just be sure to proofread your story and watch for any kind of typos and check your sentences to make sure they flow. Also, I swore I read somewhere that this was supposed to be a comedy or something but try not to go overboard. In a comedy, not everything has to be funny.
I hope you continue updating and I'll be sure to check out any further installments (because I'm too lazy to go on Serebii).