movie trailer (apple.com - quicktime)
NOTE: This spoiler was sent in by Skipper who says... "This movie was cute, funny, and somewhat meaningful all at once. I would definitely recommend it; there are many funny moments that the spoiler doesn't do justice."
The movie begins with Cady, who has just moved from Africa. She talks about how she's never been to a real school before. Her first day doesn't go so well, however. Nobody will talk to her and she ends up eating lunch in a bathroom stall because she has nobody to sit with at lunch.
The next day, Cady befriends a girl named Janis and Janis' friend Damien, who's "almost too gay to function," as Janis puts it. They invite her to cut class with them. While they are sitting out on the field, there is a P.E. class taking place.
Janis points out the Plastics--Karen, who lacks brainpower, Gretchen, whose dad invented Toaster Strudel, and Regina, who Janis describes as evil.
One day at lunch, Cady is on her way to Janis and Damien's table when a guy intercepts her first and asks if she likes her muffin buttered (obviously a sex joke). Cady is confused.
They happen to be right by the Plastics' table, and Regina sticks up for Cady and then invites her to sit with them. The Plastics have a huddle and decide to invite Cady to sit with them for the rest of the week. They also bombard her with rules--you can only wear your hair in a ponytail once a week, and Wednesdays they wear pink. Later on, Cady is talking to Janis and Damien. Janis thinks it's great; Cady can spy on the Plastics for her. Cady wonders why Janis seems to have a personal motive for revenge on Regina, but Janis stops Damien from telling her. But tomorrow is Wednesday, and Cady doesn't have anything pink to wear. Well, Damien does! Problem solved.
Cady starts hanging out more and more with the Plastics. They shop together and hang out at Regina's house, where they show Cady their book with a picture and a nasty comment about every other girl in the junior class. For Janis, it says that she's a lesbian. At one point, Regina confesses to Cady that she and Janis were best friends in middle school, but then Regina started going out with her first boyfriend. Janis, she says, was getting annoying because Regina wasn't spending as much time with her, so Regina concludes that Janis must be a lesbian.
Cady is in math, her favorite subject. She likes the guy who sits in front of her, Aaron. When she tells Gretchen and Karen about her crush on Aaron, Gretchen tells her that he's off-limits because he's Regina's ex-boyfriend, but she won't tell Regina that Cady likes him. Later on, Regina calls Cady at home and tells her that Gretchen told her about Cady's crush on Aaron. She says she doesn't mind and that she could talk to him for her. She asks Cady if she's mad at Gretchen for telling her, and Cady says that she's not, although it was a bitchy thing to do. It turns out that Gretchen is on the line, but they get the matter straightened out. Cady has survived her first three-way calling attack.
Halloween rolls around, and Cady is invited to a Halloween party. She's unaware that most girls wear lingerie and animal ears for Halloween, so she dresses up like the Bride of Frankenstein, fake teeth and all. At the party, Regina tells Aaron that Cady likes him. He seems happy about it, until Regina starts saying that Cady kept a tissue that he used once and that she has a shirt that says "I Love Aaron" that she always wears under her clothes. Then Regina kisses him and Cady, who witnesses it, storms out of the party and goes to Janis's, where Janis and Damien are watching a scary movie. She plots with Janis how to get revenge on Regina by de-throning her as the queen bee.
In the meantime, Cady still likes Aaron even though he's dating Regina now. She starts doing badly on math tests just so that she can ask him math questions to talk to him. Gretchen accidentally lets it slip that Regina makes out with some other guy after school in the projection room over the gym, but Cady is unsuccessful in luring Aaron over there in time to catch them. One day, Aaron is over at Cady's tutoring her and they kiss. Aaron realizes that it's wrong, but then Cady tells him about Regina cheating on him.
Regina is being hostile to Gretchen, who is obviously miserable as a Plastic, but she'd rather be miserable and in the clique than happy and an outsider. Cady senses this and takes the opportunity to sabotage Regina and Gretchen's friendship. At Christmas, she sends herself and Karen a candy cane from Regina, but not one to Gretchen, which makes Gretchen feel bad. At the school talent show, the CD player gets kicked and breaks. Cady saves the act by starting to sing the song and have the audience sing along.
Later on, Cady is on the phone with Gretchen, who is also on with Karen, who is also on with Regina. Regina asks Karen if she wants to go out and do something, but not invite Gretchen. The girls go back and fourth talking and reporting each others' conversations.
Regina wants to lose weight. Cady gives her nutrition bars that her mom gave to the kids in Africa to help them gain weight. The wrapper is printed in Swiss, so Regina can't read it. She starts putting on weight and can't fit into the Spring Fling dress that she reserved at the store. One day, Regina shows up in track pants on the wrong day. Gretchen, Karen, and Cady tell her that she's broken the rule and can't sit with them. Regina replies that they're the only thing she has that still fits, but they kick her out anyway. Cady has de-throned the queen bee, but it's not over yet. Gretchen and Karen are now following her around all the time, and she's the new queen bee.
Cady has a small get-together that turns into a huge party through word of mouth. She has invited Aaron. During the party, he goes up to her room and sees a picture of her in Africa before her transformation took place. It's obvious that he prefers the old Cady. Regina happens to be driving by and sees that Cady had a party without her. She storms in on Cady and Aaron, at which point Cady barfs on Aaron. In order to have the party, Cady has skipped out on Janis's art show. Janis drives by and yells that Cady is selfish and is now a mean girl and they're not friends anymore. She throws her prize-winning painting to Cady. It's a picture of them and Damien.
Regina wants revenge. She takes the book that the Plastics had and puts a nasty entry in it about herself. Then she shows it to the principal and blames Gretchen, Karen, and Cady for it. While the three of them are in the principal's office, Regina takes a bunch of photo-copied pages from the book and spreads them all over the school. Soon all the girls in the junior class are fighting about the comments in the book and are all sent for an assembly. Ms. Norbury (Tina Fey) makes them do an activity where they all publicly apologize to someone and then they fall back and let the other girls catch them. Gretchen is sorry that she's so popular and everybod likes her. Only Karen tries to catch her. Cady takes the blame for the book and sets about straightening herself out. She joins the Mathletes despite being told that it's social suicide. She decides to be nice to everyone, and when she is talking to Regina in the street one day Regina gets hit by a bus. Rumors start to fly that she pushed Regina into the bus.
Cady goes to a math competition instead of the Spring Fling. During a lightning round with an unattractive girl, Cady realizes that saying nasty things about others won't make herself any better. Cady wins the competition for her school and makes it to the Spring Fling in time to hear the announcement for Spring Fling Queen.
Surprise surprise, Cady is the winner. She takes the plastic crown and breaks it into small pieces, and then tosses the pieces out to the other candidates and some other girls, saying that they all deserve it. Then she dances with Aaron, and we assume she gets the guy in the end (gee, didn't see that coming). Janis hooks up with the president of the Mathletes. Cady and Janis renew their friendship.
So what happened to the Plastics? Regina channeled her anger into sports and became a kickass lacrosse player. Karen, who claims her boobs can tell the weather, began forecasting for the school broadcasting station. Gretchen found a new clique with a bunch of cool Asian girls. And they all lived happily ever after, we assume.