The former "Rugrats" tots now face preteen issues and dilemmas.
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.
