Earth is invaded by the Makuu Empire, led by Don Horror, who had first destroyed a space colony near Earth. Don Horror wants to dominate the whole universe and sends spaceships to create panic on Earth. While the Makuu is trying to impose its domination, Space Sheriff Gavan from the Galactic Union Patrol, arrives in his spaceship, the Dolgiran. He is the son of Tamiko Ichijouji and Voicer. When needed, he is teleported via a silver chrome combat suit using the Jouchaku process which consists of fusing Granium particles to Gavan's body. He is an accomplished athlete and has various weapons at his disposal. On Earth, he uses the name Retsu Ichijoji.
He has been played by Kenji Oba, he has played this role in six different shows or movies. First in Uchû keiji Gyaban (Space Sherrif Gavan) and then later in Sharivan and Shaider. In the special Space Cop Shaider: Pursuit! Shigi Shigi Abduction Plan in 1985. Then in one episode of Chojinki Metalder in 1987 and World Ninja War Jiraiya in 1988. And finally Gokaiger vs. Gavan in 2012 where he plays the dual roles of Ichijouji Retsu and Shirou Akebono from Battle Fever J and Denjiman respectively.