In order to win a brand new car, Clarissa enters herself and Ferguson in a contest for siblings that have extraordinary relationships. When the editor for the magazine comes to interview the close siblings, it becomes a struggle for them to pretend to be friends.

While staying with the Darlings for a weekend, Sam seems to be spending all of his time with Mr. and Mrs. Darling, making Clarissa jealous. Both Ferguson and Clarissa plan how to get rid of Sam.

There's chaos in store when Ferguson runs for school President and turns the Darling household into his campaign headquarters.

After helping Sam to land a new girlfriend, Elise Quackenbush, Clarissa feels left out when Sam cancels his plans with her to spend more time with Elise.

Clarissa gets chosen as the understudy for the lead in the school play. She is extremely happy about this 'easy job' until the lead comes down with sore throat on opening night. Ferguson tries to 'help' Clarissa learn her lines in time, but secretly has her memorizing the lines to several other different plays.

Ferguson's new friend, J. Elliot Fundsworth III is the founder of the Junior Yacht Club and Ferguson will do anything to join. However, trouble ensues when Ferguson realized that J. Elliot is really only interested in Clarissa.

Clarissa becomes worried about her parents' marriage when a debate starts between the two of them. Marshall wants to follow his dream of building a brand new mall, while Janet is more concerned about saving the trees on the same piece of property.

Clarissa's plans for a slumber party are ruined when her parents go away and ask overbearing Aunt Mafalda to stay with the kids.

After a commercial producer spots Marshall in line at the grocery store, she chooses him as 'the perfect face.' However, Marshall starts taking his new role as a male model a bit too seriously.

Clarissa finds a topic for her school project- TV. She has to watch for 24 hours in order to make observations for her report. However, a plot created by Ferguson makes her think she's lost her mind from watching so much television.

Clarissa's school guidance counselor, Ms. Cheesebrow, makes Clarissa try more 'normal' activities, such as Home Ec and Cheerleading. But Clarissa soon learns that one person's normal is another's abnormal.

After failing a magazine quiz on 'How Well Do You Know Your Daughter?', Janet attempts to get to know Clarissa better. But Clarissa gets fed up when her mom plans to take her to a concert and even dresses like her.