To All the Boys I've Loved Before by Jenny Han

Alright boys, I’m going to tell you a secret.  Every girl would LOVE to get a love letter.  She might not admit it, but it’s true.  I have mine, from old boyfriends hidden away.  Lara Jean keeps her love letters in an old hatbox that belonged to her mother.  Only Lara Jean’s letters aren’t love letters in the strictest sense of the word.  They’re letters she’s written to boys she’s loved.  They’re therapeutic, a way for her to get one with her life.  Only now, they’re missing, having been accidentally mailed to each boy and Lara’s love life quickly goes from imaginary to out of control.