Shadow Tokyo is an alternative version of Tokyo created during the climax of the Great Demon War. Using the Imperial Sword forged by her husband Tekkan Amamiya, Hinata Amamiya created Shadow Tokyo at the cost of her own life, enabling the Imperial, Paris, and New York Combat Revues to seal the Archdemon away in the realm. To prevent the demon from escaping, the three Revues choose to seal themselves away alongside the beast.
Ten years later, President G, in reality the demon Sotetsu Genan, stole the Imperial Sword to free the Archdemon from Shadow Tokyo.