A dead inventor becomes a ghost that haunts his own son's survival. GoShogun asks you to watch a kid pilot a giant robot while carrying the weight of a father's suicide, and it never separates the two. The Docougar Crime Syndicate exists to hunt him across the globe, but the real enemy is the secret his father died to keep, and what knowing it will cost him when he finally does.

A meteor lands on Earth and gives off a potent new form of energy known as Beamler. The energy drives two creations: GoShogun, a combat robot, and Good Thunder, a fortress able to teleport. The Docougar Crime Syndicate, headed by the crime lord Neo Neros, wants the secret of Beamler, but GoShogun's inventor chooses death over handing it to them. Neo Neros then goes after the inventor's son, who finds shelter with the crew of Good Thunder. Together they roam the globe, battling the syndicate's forces with GoShogun in a sci-fi mecha adventure.