Warning: There are spoilers ahead!

1. First encounter

• Book: Peter Kavinsky’s first scene was when he rolls up his black Audi the time he saw Lara Jean after her small car accident and asked if she was okay, pulls over his car and climbs out inspecting her car.
• Movie: Peter’s first scene was when Lara Jean was backing up her car in the school parking lot with her sister Kitty and almost ran over Peter.

2. Lara Jean’s letters

• Book: Kitty sent the letters because she was mad at Lara Jean for joking about telling Josh that she had a crush on him.
• Movie: Kitty sent the letters because she thinks that Lara Jean is lonely, so sending the letters would help her sister “find some romance.”

3. Confrontation about the letters

• Book: Peter asked Lara Jean in the track field about the letter he got. Then the next day, Josh approached her at her locker and asked about the letter he received. She said that she already has a boyfriend so he doesn’t need to worry about what was written there, but then she runs up to Peter when she sees him in the hallway and kisses him.
• Movie: When Lara Jean saw Josh walking toward the field track while Peter is asking her about the letter he got, she launches herself to Peter and kissed him on the track.

4. Fake relationship

• Book: Peter suggested the fake relationship inside the room after their Chemistry class and to show that he is over Gen, his ex-girlfriend.
• Movie: Peter suggested the fake relationship in front of Lara Jean’s house when he brought her home, saying that it will make Gen jealous which will help in getting them back together.

5. Ending

• Book: It ends with Lara Jean writing a letter but only “Dear Peter” was mentioned, it ends on a cliffhanger which makes the readers unsure of what her decision about her feelings for Peter is.
• Movie: Lara Jean wrote a letter to Peter saying she likes him and went to their school to personally say it to him as she read the letter out loud.