Sadamitsu the Destroyer

The protagonist of the novel is Tsubaki Sadamitsu, a young criminal and the head of the Corpse Gang, who by chance meets Rykei-dai ( "Exiled One"), an alien robot sent to Earth to apprehend criminals who have been exiled from other planets. When Sadamitsu accidentally destroys the robot's body, he learns that not only can the robot's head function without the body, but he can also use the head as a helmet to get some of the robot's abilities. Ever the gentleman, Sadamitsu agrees to use these abilities and collaborate with the robot's computer to carry out its purpose in an effort to atone for the mess his actions have produced. Even with other outside help, the Vulture's appearance as a last-ditch attempt to control the Rykei-dai makes his work more difficult.