Pinkie Pie, Ponyville's official party planner, and the happiest pony in the world, friends with everypony, you'd think she never had her moments of sadness and sorrow. How wrong you'd be to think that.

Five years ago, back on the rock farm, she finds a cave on one of her little trips on the edge of the farm, and inside she finds a lonely pony. Having discovered that her special talent was to make ponies happy, she approaches her and soon, Pinkie and this other pony become friends. However, this pony is not really a pony... well, not completely.

After an incident that scarred Pinkie since then, she moves to Ponyville to live her own life and meet more ponies to have fun with, hiding a troubled past deep under her happy facade. But what happens when said past resurfaces after so many years? Will the Element of Laughter be able to fix it, or will she turn her back on it and keep the grudge she has against it?