High school junior Lara Jean Covey (Lana Condor) writes letters to boys she feels an intense passion for before locking them away in her closet. Her latest letter is to her childhood friend Josh (Israel Broussard), who is dating her older sister Margot (Janel Parrish). Margot breaks up with Josh before leaving for college, but her leaving leaves Lara Jean feeling alone. She feels too awkward to hang around Josh again, leaving her with only one other friend, Christine (Madeleine Arthur).One night while hanging out with her little sister, Kitty (Anna Cathcart), Lara Jean falls asleep on the couch, allowing Kitty to sneak into Lara Jean's room and find her collection of letters. The following Monday at school, Lara Jean is confronted by a former crush of hers, Peter (Noah Centineo). Peter reveals he was mailed his letter, causing Lara Jean to faint. After waking up, she sees Josh approaching with a letter of his own, and in a moment of panic Lara Jean kisses Peter before running off.Lara Jean then encounters another recipient of a letter, Lucas (Trezzo Mahoro), who comes out as gay as she realizes all the letters have been mailed. She then explains to Peter she was merely causing Josh to think she lost interest in him. Peter is surprisingly okay with this, and proposes he and Lara Jean fake date each other to make his ex-girlfriend (and Lara Jean's ex-best friend) Gen (Emilija Baranac) jealous. She agrees, and the next few months go by with the whole school, along with their respective friends and families, believing the lie.However, when Peter finds Gen actually jealous, he finds himself conflicted on his true feelings. Meanwhile, Lara Jean finds herself jealous at the two. Her dad and Christine, both agree that this is the happiest they have ever seen Lara Jean. Eventually, the two go on the school ski trip together, where they confront each other about their true feelings. They proceed to hook up while alone in a hot tub. After the trip ends, Gen confronts Lara Jean, revealing Peter spent the night in her room after they hooked up. Furious, Lara Jean breaks up with Peter and storms home, where she finds Margot has returned from college. Peter then comes to her house, hoping to explain that nothing happened between him and Gen, but Josh arrives as well. Margot overhears everything, and is visibly upset when she learns of Lara Jean's former feelings for Josh. Things are worsened when after Lara Jean asks Peter to leave, she sees a video of her and Peter in the hot tub has been put up on Instagram.Lara Jean asks for Margot's help, who calms down and comforts her sister. Kitty then reveals she sent the letters. While Lara Jean is enraged, Margot calms her down when she asks why the letters had addresses on them. Lara Jean realizes she may have wanted to send them but was too afraid to do so, and the sisters forgive each other before emailing Instagram to get the video taken down.After Christmas break, Lara Jean discovers everyone knows about the video anyway, while Peter tries to tell everyone that nothing happened. Lara Jean confronts Gen about the video, who reveals she tried to sabotage their relationship as she felt betrayed when Lara Jean kissed Peter in middle school during spin-the-bottle. After talking with her dad and reevaluating the relationships in her life, Lara Jean talks to Josh, who agrees to be friends again. When she hesitates to go to Peter despite having real feelings, Kitty pushes her to do so. Lara Jean goes to see Peter, and he tells her he is in love with her. The two kiss before walking off together.
In a mid-credits scene, John (Jordan Burtchett), a recipient of Lara Jean's letter who she knew in the fifth grade arrives at her door with flowers in hand.
Storyline
Lara Jean Covey writes letters to all of her past loves, the letters are meant for her eyes only. Until one day when all the love letters are sent out to her previous loves. Her life is soon thrown into chaos when her foregoing loves confront her one by one. Lara Jean keeps her love letters in a hatbox her mother gave her. They aren't love letters that anyone else wrote for her; these are ones she's written. One for every boy she's ever loved-- five in all. When she writes she can pour her heart and soul and say all the things she would never say in real life, because her letters are for her eyes only. Until the day her secret letters are mailed, and suddenly Lara Jean's love life goes from imaginary to out of control. Teen Lara Jean Covey lives a normal, boring high school life until some unexpected letters get released to all her former crushes. These were love letters and were meant for her eyes only, until one day her sister Kitty sends them out in hopes to give Lara Jean a more interesting life. At school her life is thrown into turmoil when these boys start to approach her about their letters. Among these boys are Josh, who happens to be her next door neighbor and her older sister Margot's boyfriend, and Peter Kavinsky, her arch nemesis, Gen's boyfriend. Through out some very unusual events Lara Jean finds herself and maybe even a real relationship. Lara Jean Covey is a teenage girl who writes love letters when she gets a crush too big to handle but she never actually sends them. One day her deepest secrets are revealed and she creates and elaborate plan to save herself from being too embarrassed but it all goes pear shaped when it turns into more than fake.