When the Earth is threatened by alien invaders and giant monsters, the world relies on the Science Patrol, a special anti-monster defense agency armed with high-tech weaponry and vehicles to combat these threats from the unknown. When the Science Patrol's weaponry is ineffective and all hope is lost, one of their members, Hayata, transforms into a giant alien called Ultraman to defeat the monstrous menace threatening the Earth, unbeknownst to the other Science Patrol members, who are unaware of his secret identity.