Natsume travels to a parallel world where spirits merge, incorporating them into every aspect of people's lives. Beneath the snow and wind in Antarctica, a mysterious figure leaps, gradually receding into the distance. Atop the scorching desert, a terrifying figure stirs the sand like a roaring ocean wave. Natsume, a time traveler equipped with a system, begins as a King-class Vulcan Moth. Starting as a high school senior, he steadily rises to become the world's greatest trainer.