Five Space Cops are tasked with the mission of protecting peace throughout the universe, including Earth. However, due to prolonged peace, their discipline becomes lax. Commander Master King banishes the Space Cops to a rundown subway station for failing their guard duty. Suddenly, Serpent invades Earth and unleashes the evil Devil Monster Sep, threatening the planet. Earth Command declares an emergency, but they are pushed back by Serpent's overwhelming power. Humanity faces a great crisis. Meanwhile, a boy named Kai, searching for his archaeologist parents, accidentally meets the Space Cops and becomes friends with them. Together with Kai, the Space Cops embark on a quest to find the bones of their Guardians: Phoenix, Rhino, Puma, Randial, and Cobra. They must revive the Guardians and stop Serpent and Sep to transport them to space prison. Can these mistake-prone heroes find the Guardian bones and stop Serpent's forces?