Pinkie Pie, Element of Laughter. Best friend of everypony that would come across her. Dependable and reliable, and a very competent maker of sweet treats in Ponyville's own Sugarcube corner. But it was not always that way.

Taking place directly after Cutie Mark Sentai Crusader, during an average day hanging out with a few of her close friends on one of her days off, Pinkie Pie receives a mysterious letter, which instantly changes her mood for the worse, leaving Rainbow Dash and Twilight to feel concern for their pink friend. After gathering their other friends, They meet part of the reason for Pinkie's troubles: Strange ponies wearing black around front of Sugarcube Corner. After meeting with her father, Igneous Rock Pie, and getting admittance inside, they find that they are wrapped up in a serious matter. In meeting with relatively famous ponies, and spurned on by their curiosity, Twilight and her friends delve into Pinkie Pie's past. A time when she wasn't the crazed party pony that they knew and love. A time when the world was in danger of invasion. A time when Pinkamena Diane Pie was a leader of a group of Samurai.

This is the story of that time, and the trials and hardships that she and the rest of her family would endure to save the world from an otherworldly threat. This is the story of the Shinkenger.