On the last day of school, no one bothers to sign Lisa's yearbook, making her feel depressed about her lack of true friends[[note]]meaning that the girls she hangs out with at school -- Janey, Sherri and Terri, and the pigtail girl who bought her Lisa Lionheart doll -- don't like her enough to sign her yearbook or even be considered her best friends[[/note]] and, during a trip to Flanders' beach house, Lisa decides to ditch her nerdy persona and be one of the cool kids, which makes her popular with some local teenagers (one of which is voiced by guest star ChristinaRicci). Meanwhile, Homer goes to the beachside Kwik-E-Mart to buy some illegal fireworks.
* BewareTheNiceOnes: Lisa may have been restrained, but she got absolutely ''vicious'' with Bart the day after he showed her new friends her yearbook. She yanks him by his shirt, hisses at him over what he'd done, and was prepared to do something horrible to him with a bottle of honey before Marge comes back in the room.
** Marge's motherly advice to Lisa about her lack of friends. Lisa tries the opposite, and makes herself into some beatnik. However, her intellectual nature still shines through, but her beach friends actually appreciate Lisa's lessons on nature and why you can't drink seawater.
** Bart tries to mock Lisa with this trope the morning after he outs her. She almost kills him.
* BigBrotherBully: Bart to possibly [[KickTheDog his nastiest degree]]. Rather than be happy that Lisa is making friends, he is upset they treat him like a nerd and that Lisa is co-opting his catchphrases, and tries to sabotage Lisa's relationship.
* BorrowedCatchphrase: Lisa infuriates Bart by using all his phrases and lingo to impress her friends.
* BreadEggsMilkSquick: Homer tries to buy illegal fireworks from a Kwik-E-Mart and they're the least suspicious item on the list, despite being the only illegal one, parodying a similar scene in ''Film/AmericanGraffiti''.
-->'''Homer:''' Yeah, um, give me one of those porno magazines, a large box of condoms, a bottle of Old Harper, a box of panty shields, some illegal fireworks, and one of those disposable enemas. Eh, make it two.
** At the beginning of the episode Lisa gets annoyed at herself for wanting to bring a microscope to the beach. [[FreezeFrameBonus At the end Ben writes "next year bring your microscope" in her yearbook.]]
** Homer shoves his illegal firework into the dishwasher, causing it to start oozing a black sludge. A few scenes later, Marge can be seen furiously scrubbing at the dishes, trying to get it off. Later on, the family eats off the broken plates anyway.
* ChaosWhileTheyreNotLooking: Lisa becomes furious at Bart for revealing her true geeky nature to her new beach friends. In one scene, when Marge leaves the room, Lisa grabs Bart by his collar and prepares to pour syrup on his eyes, only to put everything back the second she reenters.
* TheChewToy: Milhouse, and he really does nothing to deserve any of it.
** Milhouse flips out when the school bell rings, and rushes off. Mrs. Krabappel reminds the rest of the class that Summer break starts at the ''end'' of school.
** As Lisa complains about how friendless she is, she points out that even Gore Vidal's kissed more boys than she has. Marge, not getting her point, states that "boys kiss girls".
* DidntThinkThisThrough: The beach kids decorate the family car for Lisa as a sign that they still view her as a friend, but fail to note that ''Homer'' would react differently to what they've done.
* EscalatingWar: Lisa is left livid over Bart seemingly destroying her relationship new friends, leading to a back and forth at the beach carnival. After she is humiliated when they take their war to the bumper cars, Lisa loses interest and walks off depressed, and Bart to suffer a JerkassRealization.
* GreenEyedMonster: Bart becomes very jealous of Lisa's newfound popularity. It culminates in him showing Lisa's friends her yearbook, revealing her nerdy, unpopular nature.
* IJustWantToHaveFriends: This episode focuses on Lisa's isolation from the rest of her classmates, sparking her voyage to remake herself.
** Reconstructed with Bart, who already is popular in their home ground, but is left disgruntled when he can't impress Lisa's friends and is stuck with Milhouse throughout the vacation (Lisa had expected he'd try steal them from her and convinced them he was an annoying dork).
* IdenticalStranger: The local Kwik-E-Mart owner at the beach looks and sounds like Apu, only he looks Sikh (has a beard and a turban) rather than Hindu.
* JerkassHasAPoint: What Bart did was cruel, but he was rightfully angry by the fact Lisa lied to the other kids and convinced them he was a nerd and stole some of his personality traits to make herself look cooler.
* MoodWhiplash: The episode switches constantly between zany comedy and heartfelt moments. The ultimate example is Lisa discovering that her new friends don't shun her, and actually show their friendship by decorating Homer's car with seashells. Lisa is overjoyed...until Homer comes out and yells:
---> '''Homer''': Sweet merciful crap! My car!
* MyGodWhatHaveIDone: Bart regrets seemingly ruining Lisa's relationship with her beach friends, and makes up for it by having them sign her yearbook.
* NiceGuy: Erin and her friends avoid KidsAreCruel and are pretty nice people. When they learn Lisa's unpopular nature, rather than shun and bully her, they decorate the family car in seashells (which turns pear-shape when Homer catches them and a flock of seagulls peck at the car when they drive home), sign her yearbook, and tell her that they don't mind -- and actually like -- that she's a brainy girl.
* NoodleImplements: Marge finding all the embarrassing sexual and personal hygiene stuff in the grocery bag, thinking he's planning some kinky night with her that she wants nothing to do with (though a later scene that shows Marge [[DidYouJustHaveSex smiling]] has led viewers to believe that Homer really did use the panty shields, condoms, enemas, Old Harper, and porno mags for a sexual night with Marge).
* ObfuscatingStupidity: Lisa initially tries to hide her bookworm side towards Erin and her friends.
* OverlyLongName: The Flanders' beach house is at Little Pwagmattasquarmsettport.
* PoliceAreUseless: Averted, the police actually manage to catch Milhouse when he rushes out of school.
* ShutUpHannibal: Lisa, [[TranquilFury quietly but furiously]], blows up at Bart for (apparently) sabotaging her relationship with her friends.
-->'''Bart''': Hey, Lise. I guess my little yearbook stunt was pretty rough but it did teach you a lesson. It's important to be yourself.
-->'''Lisa''': ''(Yanks him by the shirt into her face)'' I know '''''exactly''''' who I am. I am the sister of a ''rotten'', jealous, '''''mean''''' little sneak! ''You cost me my only friends''! '''''You've ruined my life'''''!
* TrueCompanions: Lisa and Erin, sealed by the friendship bracelet, and her and her other friends decorating Homer's car in Lisa's honor.
* YankTheDogsChain: Lisa is ostracized at school for being nerdy, then finally makes some new friends by posing as a beatnik until Bart outs her in front of them, for which she gives him a well-deserved [[TheReasonYouSuckSpeech tongue-lashing]].