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.

Ultraman Shadow, Ultraman Zearth's most terrifying adversary yet, is brought to Earth by the murderous alien, Lady Benzen to be Ultraman Zearth's assassin. Ultraman Shadow is a warrior of darkness equipped with mysterious powers. Prepare to witness the ultimate showdown, colossus versus mighty colossus, the battle ground: Planet Earth!

Inept hero Ultraman Zearth must overcome his fear of germs and grime, if he wishes to save Earth from the evil Alien Benzene and his Kaiju pet Cotton-Poppe.