Pepper the Dedenne has lived a content life with his aunt his entire life. He has spent his life as a normal Pokemon should, although he's always been intrigued by Fantasy tales. He's always dreamed of being a hero, just like in his favorite fables and fairy tales.
One day, when Pepper was just an adolescent, his home was invaded by the Persian tribe. One by one, he watched the Pokemon he cared about get trapped. Desperate for help, Pepper goes on a mission to seek the legendary Xerneas to aid him. During his journey, he meets a mysterious shiny Dedenne named Despereaux, a lone Pokemon who, after a long while of convincing, agrees to journey with Pepper. They encounter many obstacles, meet new Pokemon, and face multiple troubles along the way. It's Pepper's turn to be the hero that he's frequently read stories about. Will they reach Xerneas in time to save Pepper's friends?