
Lara Jean has never had a boyfriend. Instead, she has a habit of crushing madly on a boy, suffering in silence, and then writing him a letter to get over him, hiding it away in an old hatbox. She thinks her secrets are safe, but one day, the letters somehow get sent out, and all the boys she's ever had unrequited feelings for discover them. Unfortunately, one of them is her older sister's recent ex and their next-door neighbor, Josh.
Frantic to convince him that she doesn't feel that way anymore (even though she kinda does), Lara Jean enlists the help of one of her other crushes, one she's totally over. Peter just broke up with his own girlfriend and wants to make her jealous. With the agreement that their relationship is just for show, Peter and Lara Jean make a production of holding hands, snuggling, and smooching where everyone can see them.
But then Lara Jean actually starts having feelings for Peter. What if he doesn't feel the same way?
Worse yet: what if he does?