At Britton P. High, there can only be one person who's the top. Like, you know, the one who categorizes the losers and the popular group, who she hangs with, who dates who at the school dances, et cetera. That's Brit. But when Miranda comes to the school, she dominates the crowd with her super-posh shoes and wins over the cheerleaders single- handed. She's a natural leader, and she's from Hollywood.
When Brit finds out that Miranda is trying to steal her spot, she realizes that she has to do something. Miranda could hurt her reputation! When Miranda finds, out she realizes she'll have to fight her way into the spot.
Because there can only be one who's the Top.