Tired of being considered a "goody goody" by the popular kids, Susie tries desperately to prove that she can be a bad girl.

When Chuckie discovers that Kimi is upset, he comes to the conclusion that she hates how her room looks. The gang decides to help him redesign it for her while Angelica keeps Kimi busy. Dil tries giving advice, but they choose to ignore him. It is later discovered that she is homesick for Japan and her biological father. Chas and Kira have a big surprise for Kimi.

While the gang try on their Halloween costumes in the Finster's garage, they find TP+KF carved on the wall. Chuckie believes that Tommy has a crush on Kimi. The argument between Tommy and Chuckie escalates to where their friendship falls apart. So the rest of the gang tries to bring the two back together, but backfires. The two eventually make up when Chuckie saves Tommy from the middle school goons who were chasing him.

When a comic book starring Chuckie's favorite superhero Armadillo Dave gets cancelled, he becomes too depressed to help Tommy with his science fair project. Tommy has to buy a rat for his project, but the last rat available is a mean one. It scares everybody. Kimi made Tommy a simple one lane track for his rat, much to his disappointment as he feels he would get a failing grade for it, but needs Chuckie so he can get a good grade on it since Chuckie has done it before. The gang tries to find Chuckie a new hero to worship.

Angelica's teacher is having a baby so she brings in a hot handsome substitute teacher that Angelica falls in love with. She tries to date him by failing her assignments. Meanwhile, Tommy, Phil, and Chuckie are part of the tennis club run by Pangborn. Chuckie is trying to avoid showering at the boys' locker room, but when he takes the chance, he realizes he has nothing to worry about.

Tommy's girlfriend, Rachel is moving away, and he's cool with it, but is not sure why. However, his friends think otherwise, believing him to be in denial. Tommy tries going about his life as normal, but everyone keeps trying to show him compassion, annoying him greatly. Tommy is advised by Dil to go along with the plan so his friends will leave him alone. However, when Tommy hooks up with another girl, the gang unexpectedly have Rachel show up to surprise Tommy. Seeing him with another girl so soon is too much for her to bear, so she walks away again, leaving Tommy to cry for real this time. Chuckie then shows up at Tommy's house to comfort him.

With Stu and Didi away at an Invention Convention, Dil wants to host a viewing party for a "real" alien autopsy video with Tommy. But when both Grandpa Lou and Grandpa Boris show up to babysit the kids, they all start to have a feud. This gets even more difficult when Phil, Lil, and Chuckie show up and Dil invites 10 other kids to come see it, much to Tommy's frustration.

In the series finale, When Tommy forgoes going to the traditional opening day ball game outing with his Grandpa in order to patch things up with his former girlfriend Rachel, Lou takes Dil instead. This makes Tommy jealous as he and Dil compete to be Lou's favorite grandson during a fishing trip.

Phil has a crush on Lil's best friend and soccer teammate Wally they start hanging out more often, making Lil feel out of the loop. So Lil develops a plan to pull them apart. Phil and Wally's relationship fell apart when Lil told Wally that he does not like her. When Phil finds out that Lil lied to Wally, he becomes upset at his sister.

As Phil and Lil's birthday nears, the twins realize that they are more different from each other than they think. Phil is getting to like girls, and Lil is wearing a pink training bra. After a shocking incident, they decide to have separate parties for the boys and the girls as they try to out-prank each other.

Lil doesn't want to act like twins anymore, she would rather do things on her own without Phil. Soon after, Dil recruits himself as Phil's new twin. However, Lil's new attitude is threatening the family's trip to the Twins Canyon theme park, where twins get in for half-off, if they dress alike. Meanwhile, Chuckie refuses to participate in the mandatory President's physical education exam.

A talent scout feels that Susie has what it takes to be a singer. Her parents, however, object to her concert because they are worried that it will affect her grades. She then decides to fund the venture herself, by asking her older sister for the money.

Kimi befriends ""Z"", and punk kid, and starts to act differently, and even dies her hair pink. Meanwhile, Angelica goes on an online chatline to find advice for herself. Tommy and Chuckie follow Kimi and ""Z"" into an alley way, and have a feeling that they are going to steal something.

Tommy, Chuckie, Kimi, Phil and Lil are trying to raise money to see their favorite band live in concert, ""The Sulky Boys"" But are not even close to having enough money to buy tickets. Until they talk Dil into selling his latest invention the ""belt-quarium, which he made for his new fish Pablo. The belts prove to be a huge success, despite Angelica completly ripping off the idea. But when the fad quiets down, Tommy asks and without realizing it, forces Dil to come up with a newer invention. But when each hot item suddenly becomes lame by each day, Dil is pressured to please his brother and friends with new and more origianl creations.

Tommy decides to enter a filmmaking contest judged by his idol Martin Costomiris. But when his sci-fi movie proves to be a disaster, primarily due to the uncooperative cast, Tommy realizes that what goes on behind the scenes of the movie is far more interesting. Risking his friends, he follows them and secretly videotapes some of their private moments. When the others find out that Tommy has betrayed all of them, he's forced to make a choice: his "movie masterpiece" or his friends.

Chuckie tries to get one of the most popular girls in school, Nicole, to notice him by creating another version of himself named ""Chongo"". Nicole is instantly notices ""Chongo"" not knowing it's really Chuckie. While Phil and especiallly Tommy are less than thrilled with Chuckie's charade. Chuckie soon discovers that Nicole actually likes him as Chuckie, but is afraid to admit to her that he's been pretending to be ""Chongo"". Meanwhile, Angelica takes on the school cook by reporting in the school paper that his food is weird.

When various lawn decorations, such as gnomes, lawn orniments, ect... begin disappearing from the neighborhood everyone suspects Dil as the theif. But when Dil catches Tommy redhanded he decides to take the blame anyway. Which means being grounded and not being able to visit the museum. It is later revealed that Tommy is the thief, only he never knew it, because he was sleepwalking. Meanwhile, Angelica has to mentor a bratty little girl, who is basically a smaller version of herself.

When Betty and Chazz take Tommy, Phil and Chuckie to the great outdoors for rafting Tommy's secret fear of the water is exposed and tested after getting lost. When he was young he had a near death experience and almost drowned, ever since then he's been afraid of the water. But when Phil's life is in danger and Chuckie is too scared to help him out, Tommy must put aside his fears to try and save his friend.

When Tommy's newest film makes him famous, Dil worries that his big brother might forget all about him. Meanwhile, Angelica trains Chuckie on the fine art of lying.

Grandpa Lou takes over Stu's job of chaperone for the class field trip to the Human Body museum, and starts to embarrass Tommy. Meanwhile, Dil is hospitalized for a throat infection.

The kids try to get a date to the Valentines Day school dance with their crushes.

Dil is convinced that aliens are coming. Meanwhile, Angelica tries to be a nicer person to get Sean's attention.

The kids take an aptitude test to get a clue as to what they want to be when they grow up, but they are not happy at all about the results.

An older girl, Francine, picks on Tommy. Angelica is loving every minute of it! Does Francine like Tommy, or is she just a pest?

Kimi becomes obsessed with her Japanese heritage when she and the gang have to search their family trees as a school project.