The series takes place in a retro-futuristic setting, where the Shizuma Drive ends the depletion of petroleum resources and the need for nuclear power. The system is a non-polluting recyclable energy source that powers everything on land, sea and air. Ten years prior to the events of the series a team of scientists, led by Professor Shizuma, created the revolutionary system. In the process they nearly destroyed the world and one of their own, Franken von Vogler, was lost in the event that went down in history as the "Tragedy of Bashtarle." At the start of Giant Robo, the BF Group is in the middle of recreating the event with aid from the resurfaced von Vogler.
The story explores a society completely brought down, within the span of one week, because of dependency on a single energy source and a state of prosperity tainted by compromise and deceit.
The BF Group (BF団, Bīefu dan) is the main antagonist of the series. Their origin is unknown, but not so their reason to be: to lead mankind down a road of ruin. The Group's forces consist of mechanical monsters, foot soldiers and Experts (エキスパート, Ekisupāto), individuals with superhuman powers.
The most powerful Experts form the ruling cadre of the organization, the cabal of the Magnificent Ten (十傑集, Jūkesshū). Its members swear allegiance to Big Fire (ビッグ・ファイア, Biggu Faia), the Group's founder and leader, with faltering loyalty punishable by death. At the time of The Day the Earth Stood Still, the Ten are gearing up for the final showdown with the IPO.
The International Police Organization (国際警察機構, Kokusai Keisatsu Kikō) is the BF Group's counterpart in the Giant Robo universe. The leaders of the world acknowledged Big Fire as a threat to world security and signed the charter creating the IPO. The IPO's methods are information and espionage, looking to bring down the BF Group rather than defeating them in an all-out war.
However, to counter Big Fire's superhuman elements, "Experts" are recruited and granted special international jurisdiction. The agents assembled are known as the Experts of Justice (正義のエキスパート, Seigi no Ekisupāto). Working with the Experts from the Peking Branch is Daisaku Kusama. While he does not possess any special powers, Daisaku is the one and only master of Giant Robo. Constructed by Daisaku's father, Giant Robo is the IPO's trump card against Big Fire.
