Ferguson embarrasses Clarissa at school and so she is out to exact revenge using a straight jacket and balloons. Sam's father wants him get into the football team and he is determined to not be in it, with Clarissa's help.
Ferguson and Clarissa have been fighting for control of the TV when Clarissa's mother decreed no TV for a week. The problem then becomes about how to fill in the time without getting on each other's nerves.
Clarissa wants to buy a car but needs to get the money first. She then sets out to raise the $1500 needed. When Clarissa has no success getting the money out of her parents, she decides to sell Christmas cards, in the middle of the year.
Clarissa finds her Aunt Mafada's overly affectionate mannerisms annoying. She decides to haunt the house to encourage her to leave early. It backfires when it turns out that Aunt Mafada is interested in the supernatural.
Ferguson is being nice to Clarissa but she is suspicious of his motives. When she notices her Walkman has disappeared she manages to get to the bottom of it. Marshall receives a chain letter and Janet is horrified when he destroys it.
Clarissa is convinced that her parents are trying to have another baby. To help persuade them to not have a new baby, she enlists the aid of Ferguson. Sam needs to come up with a new science investigation and Clarissa gives him an idea.
Ferguson does an IQ test and, when he finds out that he is in the top 5% of the country, he becomes even more obnoxious, convinced that he is a genius. To make money, Ferguson decides to go on a TV game show called 'Brain Drain'.
It's Clarissa's parent's wedding anniversary and she decides to make them a cake. The trouble is, she has never made one before. Meanwhile, Janet and Marshall are having a disagreement over how to celebrate the day.
Clarissa wants a job at the Baxter beach carnival but her parent's think she is too young and say no. She then sets out to get them to change their mind. They finally say yes, but the job doesn't quite work out how she expected.
Clarissa doesn't want to go to Ancient Greece pageant day at school so she fakes being sick. Her parents don't believe her until she really does become sick. Then the pageant is revamped and suddenly Clarissa wants to go.
Clarissa gets a major crush on local weatherman Flip Fontana. Her rational head is horrified by the foolish state of her heart. Despite her best efforts, she can't stop daydreaming about him and trying to concoct ways to meet him.
Sam stays with the Darlings while his father is away and becomes the perfect son. Sam and Clarissa are working on a school project, but he spends so much time being polite to her parents, that he never has time for Clarissa, and she feels left out.
A great debate begins after the Darlings realize that Marshall's dream project is the same planned mini-mall development being protested by Janet. Clarissa worries that the debate may result in divorce.
Clarissa is picked as the understudy for the lead actor of the school play. She's overjoyed by the 'easy' assignment until the lead falls ill on opening night. Clarissa attempts to quickly learn her lines but Ferguson's help interferes.
Clarissa's overbearing guidance counselor encourages her to participate in normal teenage girl activities. After giving the recommended activities a try, Clarissa decides that being normal is overrated.
After being left alone for the night, Clarissa and Ferguson take turns scaring one another. Over the course of the evening, the Darling war continues escalate until an unexpected guest frightens them both.
Clarissa turns to her computer to help her finish an assignment for which she must write a poem. Not only does the computer "write" a strange but well-loved poem, but also Clarissa is chosen to represent her school at a banquet for young poets.
Sam's mom comes to town to play in a roller derby match. Although she is the "Most Valuable Slayer," she announces that she wants to quit the derby and take Sam back to Seattle to live with her for good.
Clarissa is broke and decides to get a job. She declines to use Ferguson's job placement business, but lets the librarian help her with her resume and job search. Clarissa gets multiple job offers, all of which she accepts.
Janet recruits the whole family to participate in Volunteer Day at the Children's Museum. Clarissa desperately wants to get out of this assignment and lucks out when the museum closes because of boiler problems.
Ferguson has fallen in love and is asking everyone for advice, including Clarissa, who wants to give him the worst advice possible. Yet every bad idea she gives him works in his favor and all the girls go crazy for him.
Sam sets up himself and Clarissa on a double blind date. Clarissa is beseiged by visions of a blind date from hell. But after Sam describes how cool her date is, she begins to think that she might be the geek.
Clarissa likes Clifford, but she isn't ready to go steady. He dates another girl who spreads a rumor that Clarissa is too fickle to commit. Clarissa decides to prove her wrong by going steady with another boy.
Clarissa goes to music class and the only instrument left is the flute. It used to be a drag to play but she's been playing effortlessly and beautifully. Mrs. Doppeldew, the music teacher, wants Clarissa to do a flute solo at next week's music recital.
During a party, Clarissa falls for a drummer named Paulie while pretending to be a 'hypercool' dressed character called Jade. Clarissa initially assumes the Jade alter-ego when meeting Paulie but eventually reveals her true self.