When Twilight Sparkle's crown is stolen from the Crystal Empire, she pursues the thief, Sunset Shimmer, into an alternate world where she finds herself turned into...a teenage girl! To regain her crown and return to Equestria, Twilight must learn how to fit into this strange, new world and defeat Sunset Shimmer in a competition to become crowned Princess of the Fall Formal at Canterlot High. Luckily, she will have the assistance of Spike and five teenage girls who remind her of a certain group of ponies back home.