You think you know me, but you don't!

Confident senior Jo begins the new school year by breaking her own cardinal rule: don't get involved in girl drama. but when she sees timid Abby preyed upon by Queen Bee Mandi and her minions, she takes sides in a viciously funny girl-world-war that turns North Shore High School upside down.

Cady Heron is a hit with The Plastics, the A-list girl clique at her new school, until she makes the mistake of falling for Aaron Samuels, the ex-boyfriend of alpha Plastic Regina George.