In the region of Kalos, an old tale spoke of two legendary Pokemon, Xerneas and Yveltal, who were said to appear every 1000 years to clash with each other. The myth became a reality when the two showed up inVaniville Town one day, wrecking havoc to everything in the area.

With their homes destroyed, X, a prodigy in battling who went into seclusion after an incident related to to the paparazzi, was forced to go on a journey with his childhood friends: Y, a Sky Trainer in training; Trevor the scholar-to-be; Tierno the dancing expert; and Shauna, who aspired to become a Furfrou Stylist. Under the constant threat of the ominous Team Flare, who was after X's mysterious Mega Ring, the five young trainers must stick together and depend on each other to weather through each challege and seek what they find, including an answer to the mystery of Mega Evolution...