(Dragon Bal Z Narrator voice) A long time ago there was a great battle fought on the Planet of the Kai. The battle was between Goku and the monster Kid Buu. Buu was thought to have been destroyed by the Spirit Bomb, but unknown to Goku he escaped to Equestria before he was completely destroyed. Arriving in a weakened state, he absorbed the first pony he came across, which happened to be the filly known as Pinkamena Diane Pie.
This is the story of adventure, friendship, violence and lazer beams. But more importantly this is the story of how Pinkie Pie got her Cutie Mark. (Abridged series are semi-cannon especially Friendship is witchcraft)