©2009 Shusuke Amagi/Miyuu/Fujimishobou/Regios Partners

Regios rely on selenium as a source of fuel. Because this element can only be extracted in special mines, fights constantly erupt among the regios and their residents for control over the mines.

©2009 Shusuke Amagi/Miyuu/Fujimishobou/Regios Partners

Chrome Shelled Regios opens with the admission of Layfon Alseif, the story’s main character, to Czerni, a regios that is a school. Layfon breaks up a fight between other students in a flash and saves a girl named Meishen. Although he was born with the powers of a bugeisha, he decided not to become one of these warriors after he was expelled from his home regios for causing an accident.