Set in 2097, most of Earth's kaiju live on an island out in the Pacific Ocean called Godzilla Island, which is monitored by G-Guard. The creatures living on the island include Godzilla, Godzilla Junior, Mothra, Mothra Leo, Rodan, Fire Rodan, King Ghidorah, Mecha-King Ghidorah, Mechagodzilla (the Heisei version), Anguirus, Gigan, Hedorah, Destoroyah, Baragon, King Caesar, Moguera, Megalon, Battra, SpaceGodzilla, Gorosaurus, Kamacuras and Jet Jaguar.

Ultraman Zearth hails from The Land of Pikari in Nebula Z95. He has a big red face and dislikes dirt, and will go to great lengths to wash it off his hands. His goal is to clean the polluted Earth. He transforms with an electric toothbrush, which is consistent with his hygiene fixation. He's not quite adept at being a superhero, but at least he tries his best.