This story is a sequel to Kingdom Hearts: Princess Twilight Sparkle
After arriving to Equestria early, Sora helps Twilight figure out what the mysterious chest is and why it's there. Twilight decides the only with more information is the abandoned Castle of the Two Sisters and the group heads there for research, much to Spike's dismay. After a while, the rest of the group goes to the castle for their own reasons; Applejack and Rainbow Dash try to prove who's the most daring pony, Rarity tries to restore ancient art, and Fluttershy is accompanying her, but Pinkie was currently ringing the school bell to the day...or was she?
When entering, everypony's imagination starts to run a little too wild for their own good. Twilight and Sora, on the other hoof, are perfectly calm, but not for long when they find two secret journals...and one of them doesn't belong to anypony in Equestria.