Training Days, Part 1

Having clearly seen Kite's power, and how utterly hopeless they are, Yuma and Astral are keenly aware that they cannot easily recover. At that time, Yuma talks to his grandmother. She mentions a mysterious old man named Roku at a Duel Sanctuary, who owns a wooden statue of the Legendary Monster Dark Magician, who is waiting for Yuma and his crew.

Synopsis excerpt via Kitsu.