As a certified stand-up bro, Nick Maguire knows that some things in life are sacred: Do not skip ab workouts. Never back down from spicy foods. And always accept the outcome of Rock, Paper, Scissors. For these are the revered doctrines of The Bro Code, rules of conduct that have been passed down through the ages from bro to bro.

Heading into his senior year, Cassidy High's star soccer player has his priorities straight and intends to spend his time playing sports, hanging out, and living by the code. But when his best bro Carter's sister Eliza returns from studying overseas, the awkward, academic girl Nick remembers is different.

Carter might be Nick's bro, but Eliza becomes his whole world—and choosing between them is unimaginable. Ultimately, Nick needs to decide if being with the girl of his dreams is worth breaking The Bro Code's most important rule of all: never date your best bro's sister . . . because he simply can't have both.