In ancient times, Camaron Palace faced imminent destruction until Sir Aaron, the revered Guardian of Aura, intervened, sacrificing himself to prevent a kingdom clash. To honor his heroic act, an annual tournament is held. Satoshi, a talented Pokémon trainer from Kanto, triumphs in the latest competition and inherits Sir Aaron's staff. This staff harbors Lucario, the loyal Aura Pokémon once in service to Sir Aaron. However, haunted by memories of abandonment, Lucario flees upon awakening. Meanwhile, Mew whisks Pikachu, Satoshi's companion, to the mystical Tree of Beginning. Only Lucario knows the path, but harbors distrust towards humans. To rescue Pikachu, Satoshi and friends must earn Lucario's trust, journeying to the legendary tree and unveiling ancient secrets.