Rosie Graham is an aspiring writer who moves to the beach town of Emerald Bay, California, to work on her new novel. She finds an apartment, but due to a mix-up, she ends up sharing it with her childhood friend, Lucas, a charming, laid-back surfer who is training to become a marine biologist. As they settle into their unexpected living arrangement, Rosie realizes Lucas is not the carefree boy she remembers, and an undeniable chemistry starts to grow between them. They agree to a "no-strings-attached" living situation, but as their professional and personal lives intertwine, they start questioning the rules of their arrangement, leading to a heartwarming and often hilarious journey of self-discovery and romance.