Katsuto Asahi is the protagonist in the film Ultraman Zearth and its sequel. The human form of the Ultraman named Zearth, Asahi hails from the Land of Pikari in the Nebula Z95. Coming to Earth to clean the polluted planet Asahi brought with him an incredible hygiene obsession and a fear of dirt. Joining the MYDO, disguised as a gasoline stand, Asahi was relegated to the position of janitor because his fear of dirt interfered with his training stopping him from becoming a full fledged member. However when the team went out Asahi would use the time alone to transform into his true identity Ultraman Zearth.