Each chapter of this is an individual story. Here's a summary for each one.

Chapter 1: Y Must Moving Day Be So Soon? -

Sid has to move away because Ronnie Anne's emotional abuse is becoming too much of a problem. All that's left to do is suffer through having to say good bye to her family.

Chapter 2: The Birth Road to Burger King -

It's Sid's 14th birthday but she's not in the best of moods. While on the drive to her party, all she can think about is how much her life sucks.

Chapter 3: We Could All Use A Little Change! -

Adelaide meets her original counterpart. Sid's worried something bad will happen but everything goes just fine.

Chapter 4: Kenan It Clean -

Sid watches the 2021 Kids' Choice Awards with a friend. Afterwards, the two of them clean up litter in his home town.

Chapter 5: Almost Done -

Sid visits the original Sid and Ronnie Anne and asks them for a favor. Meanwhile, she tells them about the time she got amnesia. After that's all done, Sid finds out something bad is happening at her mom's zoo.

Chapter 6: OTHER SID-NIFICANCE -

While at the North Pole to try to find out something Izzy really wants to know, Sid is suddenly sent to another world where she's an actress and her life is a TV show. Luckily, she's able to make it back very quickly.

Chapter 7: Still Not Friended! -

In an attempt to get them to stop hating each other, Adelaide talks Sid and Ronnie Anne into singing for their moms on Mother's Day.

Chapter 8: Being Evicted Is The Worst! -

Sid ends up in some other universes for quick moments.

Chapter 9: E3, Finally! -

Narrated by Emolga instead of Sid, this chapter takes place on a plane. One of the passengers gets Emolga's intrigue when he claims he can foresee who new Super Smash Bros. characters are going to be when he goes to sleep.

Chapter 10: On Second Thought, Luan DOES Suck -

Sid does everything she can to try to help her friend's self-loathing sister cheer up. This chapter features a song being given a completely new meaning despite it barely being altered.

Chapter 11: SpongeBob Now Has A Down Smash! -

Several other characters join Sid to speculate what content will be in Nickelodeon All-Star Brawl.

Chapter 12: The Sidonniecoln Week -

Sid, Ronnie Anne, and Lincoln have to spend a week on an island. Don't worry. They're not castaways. They're there by choice.

Chapter 13: Project Merry Vic-Mas! -

Sid invents something that turns her into a baby so she can talk to Mel and Vic on their first Halloween. But, oops, she was supposed to interview Nick All-Star Brawl characters that day and now she can only talk to babies.

Final Chapter: She's a Wonderful Sid -

The Purple Heart Pain and Sid work together to try to find a time machine in the hopes that they'll be able to use it to make it so they never hated each other. But what ends up happening instead is Sid wishes she was never born and the wish comes true.