AJ is a buttoned-up, responsible student attending a high-achieving high school in Michigan; she lives with her mother, stepfather, and two younger half sisters. Della, a free-spirited wild child, spends as much time as possible on the beach with her friends and older siblings every summer with her father in Florida. The catch: both are Adelaide Beloise Jepsen, who does everything she can to keep her school and summer lives separate. When her middle sister crashes her carefree summer getaway, Adelaide will have to reconcile the two sides of herself-- and face the fact that it is perfectly okay not to be perfect all the time. -- adapted from jacket