Initially appearing in Space Sheriff Gavan, Den Iga is attacked by a monster called Buffalo Doubler, member of the Space Mafia Makuu. Den is seriously injured in the attack when he is found by Gavan, who takes him to Planet Bird for medical assistance. Qom, leader of the Galactic Union Police (銀河連邦警察 Ginga Renpō Keisatsu?), is impressed by Den's courage. Den returns in the final episode of Gavan, saving Gavan himself in his newly acquired form of Space Sheriff Sharivan during Gavan's final battle. After Don Horror is defeated, Sharivan is assigned to Earth and is partnered together with Lily from the planet Bird as he deals with the threat of the Madou Space Crime Syndicate on Earth.