By chance, two incumbent policemen rescued Princess Stella from an alien planet. The princess turned them from ordinary policemen into super-powered police officers. The alien villains, who followed the princess to Earth, found that they could use the negative energy of humans (i.e., greed, laziness, timidity, and fear) to awaken the black phoenix and conquer the entire universe. After the transformation, Police Kai needs to assist Princess Stella to find the “fifthelement” on the earth, so as to defeat the dark forces, protect the earth, and maintain justice.
(Source: Namu Wiki, Movie Douban)