Once, this world was ruled by the Evil God Dragon Diabolos, who united the monsters and drove them into a frenzy. But fourteen years ago, a boy named Zard, then seven years old and called the Hero, defeated Diabolos, calming the monsters and ushering in an era of peace. However, four years later, Diabolos revived, and the monsters began to rampage once more. Zard set out to confront Diabolos again, but he never returned... In the year 4996, Kai, Zard's close friend, embarked on a journey to verify whether the "coexistence between humans and monsters" that Zard had spoken of was truly possible. During his travels, he encountered a mysterious boy named Izayoi, who could communicate with monsters, and a dark-skinned swordsman named Jend, who appeared to be a survivor of the Dark Elves. Seeing in them the potential for "coexistence between humans and monsters," Kai began to journey with them...