Robou is a corporate drone with an extraordinary passion for giant humanoid robots. One day, he's deeply hurt when a colleague bluntly states, "There's no need for giant humanoid robots." That very night, he's approached by beings from another world who plead with him to "fight using a giant robot." After some hesitation, Robou chooses to reincarnate into this new world. There, he finds himself inhabiting Volcamion—a mighty humanoid mecha revered by the Volcami Empire.