Toymaster

A teenage mechanical genius from Japan. Unlike Winslow who uses old-fashioned toys, Hiro's inventions are inspired by anime and manga, including a giant Batman-Superman robot.

Hiro Okamura, is a teenage mechanical genius from Japan. He targets Metallo, claiming the cyborg's body was based on a material stolen from his grandfather. Hiro later becomes an ally to Superman and Batman in destroying a kryptonite meteor that threatens the Earth by building a giant Composite Superman robot, in which Captain Atom willingly volunteered himself to piloting the robot and seemingly sacrificing himself once hitting the meteor on impact.

Okamura fakes his own kidnapping at the hands of the original Toyman, Winslow Schott, forcing Superboy and Robin to search through his complex to save his life. Realizing his loneliness, Superboy and Robin extend their friendship to the boy. Okamura joins Robin and the other Teen Titans at Titans Tower for Superboy's funeral, clutching a Superboy action figure. Okamura later offers to assist Batman and Superman in their quest to rid the world of Kryptonite, using spider-like nanobots to collect Kryptonite molecules in the air. But the duo refuse his help. His offer becomes a necessity as Lana Lang, in a last-ditch effort to get rid of Kryptonians and keep LexCorp afloat, turns a set of Kryptonite caches into "dirty bombs", which irradiate the entire planet. Hiro comes to the rescue, settling for a Power Girl-bot to "date". Instead, he gets his dream date, a dinner in Paris with the real Kara, and the status of honorary member of the Justice League.

Okamura is a noted genius who uses and creates more technologically advanced devices than the traditionally-constructed contrivances the sinister Toyman, aka Winslow Schott, uses and his work is largely whimsical in nature. Many of his inventions are inspired by anime and manga, including giant mecha (notably his giant Composite Batman-Superman robot).