The Perfectionists is a book series written by Sara Shepard.
Ava, Caitlin, Mackenzie, Julie, and Parker are all driven to be perfect—no matter the cost. At first the girls think they have nothing in common, until they discover that they all hate the same person: Nolan Hotchkiss, who's done things to hurt each of them. They come up with the perfect plan to murder Nolan—jokingly, of course. They'd never actually go through with it. But when Nolan turns up dead in the exact way they'd discussed, the girls suddenly become prime suspects in his murder. Only, they didn't do it. So who did? Unless they find the real killer, and soon, their perfect lives will come crashing down around them