Shiki is the sole human denizen of the Granbell Kingdom, a fantasy theme park on the robot-inhabited planet Granbell, which Rebecca derives his surname from. As a child, he learns how to use Demon King Ziggy's gravity-based Ether Gear, a superhuman ability that reconfigures the flow of latent "ether" energy in his body into that of a machine, allowing him to change the strength and direction of gravity for himself and others. Shiki aspires to make as many friends outside his planet as possible, but is socially awkward around other humans due to spending most of his life among robots.
