After the defeat of Queen Chrysalis and King Sombra, and Twilight becoming an alicorn and new princess, The Mane 6 and Spike send an invitation to Sonic and friends so they can celebrate with her. All things are going well, until a mysterious pony steals Twilight’s crown and escape into a portal, which leads to a different world. Making no hesitation, Sonic jumps in first as Tails, Amy, Twilight, Knuckles, and lastly Spike following along.

The new world they ended up in was completely different from Equestria, but the big change was that Twilight was a human. Sonic, Tails, Amy, and Knuckles were that same, except they were taller now. And Spike was a dog. With these changes, they must face school itself in order to get the crown back.