Penny Harris just ruined her life.

As one of the most popular girls in school, she's used to being invited to every party, is dating the Jordan Parker, and can't wait to rule senior year with her best friend, Olivia. But when Penny wakes up on Jordan's lawn the morning after his first-day-of-summer bash, she knows something went horribly wrong the night before.

She kissed Kai Tanaka.

Kai, her longtime nemesis. Kai, Olivia's boyfriend. Penny can't figure out what could have inspired her to do it--she loves Jordan and she would never hurt Olivia--but one thing's for sure: freshly dumped, and out a best friend, the idyllic summer she pictured is over.

And despite the fact that Jordan seems to be seeking comfort (and a whole lot more) in Olivia, all Penny can think about is winning him back. Kai wants to save his relationship too, so they come up with a plan: convince their friends that they really do have feelings for each other. After all, everyone forgives a good love story, and maybe seeing Penny and Kai together will make Jordan and Olivia change their minds.

But as summer heats up, so does Penny and Kai's relationship, and Penny starts to question whether she's truly faking it with Kai, if he's really as terrible as she always thought he was, and if the life she's fighting so hard to get back is the one she really wants.