Long ago, there existed an evil spirit that waged a war to conquer the human world. Defeat drove him back to the realm of darkness, but not before vowing to return and exact his revenge. A thousand years later, the world has all but forgotten the name of Arago, Emperor of Doom. When black clouds smother the bright city lights of Shinjuku, and a sinister laugh drowns out the dying hum of electricity, the people of the world plunge into terror, unprepared for the evil spirit's return! An ancient fortress of stone appears over the modern glass buildings of the city, and as the armies of the human world launch an attack, their own weapons turn against them, rendering them useless. In the face of this overwhelming power, hope is no where to be found. But not everything is lost! As despair grips the city, five young men emerge, wearing mystical armor said to grant strength enough to defeat Arago once and for all! But despite the might of their armor, Ryo of the Wildfire, Toma of the Heavens, Shu of the Stone, Shin of the Torrent, and Seiji of the Nimbus, will have to join together and learn to work as a team if they are to have any chance of defeating the armies of the Empire of Doom, including the Four Warlords, who possess mystical armor of their own!