Elle's senior year begins with classmates gossiping that she and Noah are breaking up. This makes her fear elevate as Noah has befriended an attractive British girl named Chloe on Instagram. Elle and Lee are planning the kissing booth again for the Charity Fair. So, he is trying to convince her to ask Marco Peña, the new transfer student dubbed the new "Noah Flynn," to be one of the kissers. Beating Marco on the dancing game, she forces him to participate in the booth. Noah suggests Elle apply to
Harvard, which clashes with her lifelong plan to study at
University of California, Berkeley with Lee (where their moms met and became best friends). So, Elle does it secretly. Talking with her father about college tuition, Elle learns money is a problem, so decides to participate with Lee in a dance competition with a huge cash reward for first place. Elle visits Noah in
Boston, meeting his new friends and Chloe, making her even more insecure. Finding Chloe's earring under Noah's bed causes her to leave Boston early. Confronting Noah, he assures her nothing has happened between him and Chloe and asks her to trust him, though she is still skeptical. Lee slips during one of their practice sessions (later revealed to be fake) so proposes that Marco become her dance partner, which she is not too happy about, but eventually does. As Marco and Elle start spending time together, they grow closer, and an attraction starts to develop between them. Unbeknownst to Elle, Lee is having problems with Rachel, as Elle goes everywhere with them so does not give them alone time. After forgetting Rachel waiting at the movies, she asks Lee to talk with Elle, which he promises but never does. The
Halloween Dance arrives, and Lee forgets to tell Rachel they changed costumes (Rachel was a marshmallow while Lee and Elle were going to be graham crackers making a
s'more), further upsetting her. Elle shares a dance with Marco, almost kissing him but she stops the kiss when she realises that the OMG’s are watching and judging. Lee finds Elle's application to Harvard in his car trunk, angering him. Elle and Marco excel at their competition performance, and she kisses him at the end of their dance, not knowing Noah was in the crowd, causing him to exit quickly. At
Thanksgiving dinner at the Flynn's, Noah brings Chloe, which upsets Elle. Lee then confronts her for not telling him about her application to Harvard and Rachel is also upset with her. When Rachel discovers Lee never spoke with Elle she leaves. When he catches up with her, Rachel breaks up with him. Elle unsuccessfully tries to convince Rachel to reconcile with Lee. She also returns the earring to Chloe, who confirms it is hers. Later on, Chloe confesses to Noah she had slept in his room one night when he was away so must have lost it then. The carnival day arrives, and Lee and Rachel reconcile after being blindfolded and kiss at the kissing booth. Elle is also blindfolded and is approached by Marco, who wants to talk with her about their feelings. Although she admits they have chemistry, she tells him she loves Noah and goes looking for him at the airport. At
LAX, Chloe tells Elle that Noah went looking for her, and she finds him in the park where they first kissed. He confesses he was embarrassed as he initially was not doing as well at Harvard as he had hoped. Noah also wants a connection with Chloe like Elle has with Lee. They then make up. A few months later Noah returns, and Elle, Lee, and Rachel graduate. Lee shares with Elle that he was accepted at Berkeley and asks if she received a response. She tells them she was waitlisted at both Berkeley and Harvard. When Elle opens both envelopes in her room, it turns out she was accepted to both universities, so she has to make a decision: go to Harvard with Noah or Berkeley with Lee. ==Cast==