The series was licensed in North America by Media Blasters in 2003.
The story stars Tsubaki Sadamitsu, a young delinquent and leader of the Corpse Gang, who has a chance encounter with an alien robot working to capture banished intergalactic criminals who are arriving on Earth named Ryūkei-dai (流刑台, lit.
When he ends up causing the robot's body to be destroyed, Sadamitsu discovers that its head can operate independently without the body, and wear the head as a helmet to gain some of the robot's powers.
Ever-chivalrous, Sadamitsu becomes determined to make up for the mess his actions have caused, and accepts using these powers and working with the robot's computer to take up its mission.
Though he receives other outside assistance, his job is made harder with the appearance of the Vulture, a last-ditch effort to keep the Ryūkei-dai under control.