Chrome Shelled Regios

In a future where pollution has led to the spread of corrupted creatures, humans reside in mobile cities known as Regios. One of these is Zuellni, a city structured entirely as a school. Layfon Alseif, a freshman, enrolls there and is assigned to the 17th Martial Arts Studies Unit. He joins under the leadership of third-year student Nina Antalk and takes part in various missions.