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

Every summer, Belly and her family head to the Fishers’ beach house in Cousins. Every summer is the same ... until Belly turns sixteen. Relationships will be tested, painful truths will be revealed, and Belly will be forever changed. It’s a summer of first love, first heartbreak and growing up — it's the summer she turns pretty.