A coalition of some of the galaxy's most ruthless alien monsters have joined forces to conquer Earth. They are however opposed by the heroic "warrior of light" Ultraman Mebius from Nebula M-78 who is the current successor to a long line of super powered "Ultra Brothers" who have protected the Earth from monster attacks for 40 years. The giant aliens resurrect the monstrous "super monster" U-Killer (Ultra Killer) Zarus, who was defeated by the Ultra Brothers in the early 80s and now lies dormant in Kobe Bay, Japan. Unable to defeat their combined might, Ultraman Mebius is defeated by the aliens but is soon rescued by six of his Ultra Brothers who have returned to action after nearly twenty years of retirement.