My Little Pony

Plot
Set after the events of "Magical Mystery Cure", the newly crowned Princess Twilight Sparkle and her Ponyville friends arrive at the Crystal Empire for a royal summit with Princesses Celestia, Luna, and Cadance; Twilight still struggles with the fear that she is not ready to be a ruler. Sunset Shimmer, a former and bitter student of Celestia, sneaks into the castle that night and steals Twilight's crown, one of the Elements of Harmony, leaving a fake in its place. As Twilight chases Sunset, the crown falls through a magic mirror and Sunset dives after it. The princesses inform Twilight and her friends that the mirror leads to a different world. Celestia tasks Twilight with entering this world to retrieve her crown before the portal closes again for thirty moons, or else the Elements of Harmony borne by her friends will no longer protect Equestria. Celestia insists that Twilight must travel alone, afraid to upset the balance between the two worlds. Despite this, Twilight's dragon assistant Spike anxiously jumps in after her as she enters the mirror.

On the other side, Twilight and Spike find themselves transformed into a teenage human girl and dog, respectively, outside of a large high school building in an alternate world inhabited by humans. While struggling to adjust to her new body and surroundings, Twilight recognizes several of the faculty and students as ponies she knows in Equestria, including her Ponyville friends: Applejack, Fluttershy, Pinkie Pie, Rarity, and Rainbow Dash. She quickly befriends them, helping to bridge the animosity that Sunset had created between them in the years prior to Twilight's arrival.

Twilight discovers that Fluttershy has found the crown and turned it in to Celestia, the school principal, who mistakes it for a prop meant to be given to the student who is elected Princess of the Fall Formal. Twilight decides to regain the crown by running against Sunset, who has easily won the title for three consecutive years due to her bullying and coercion of the student body. Owing to the shortage of time and the school populace's unfamiliarity with Twilight, the group arranges an elaborate song and dance number at the school cafeteria to announce her candidacy, which proves an infectious popular success. Aided by the students Snips and Snails, Sunset tries sabotaging Twilight's chances by releasing humiliating videos of Twilight behaving like a pony, and later framing her for wrecking the formal decorations in the school gymnasium. However, Twilight's new friends, including Sunset's ex-boyfriend Flash Sentry, help to counter these ploys and improve Twilight's popularity among the students, even after Twilight confides in them the truth about her being a pony princess and the need to recover the crown before the portal closes.

At the formal, Twilight wins the election and the crown, but Sunset steals it after threatening to destroy the portal. Upon donning the crown, Sunset transforms into a demonic creature and uses her newfound powers to brainwash much of the student body into becoming her army with which to invade Equestria. When Sunset tries to attack Twilight, her friends race to save her, evoking the crown's magic that protects them and temporarily gives them pony-like attributes. The magic of their friendship reverts Sunset to her human form and breaks her spell on the other students. Sunset becomes repentant, and Twilight asks her friends to become Sunset's new friends after she is gone. Twilight spends time celebrating with her friends at the formal before she and Spike take the crown through the portal, which closes behind them. Twilight and Spike return to Equestria, transforming back to their original forms on arrival and reuniting with their old friends. Twilight realizes her experiences in the other world have helped to boost her self-confidence in her ability to carry out her royal duties.