Chrome Shelled Regios: Secret Side  

Koukaku no Regios - Secret Side, Chrome Shelled Regios - Secret Side, 鋼殻のレギオス シークレット・サイド

This school fantasy tale takes place in the distant future, where polluted creatures have overrun the earth, compelling humans to dwell in mobile cities known as Regios. One such city, Zuellni, is a self-contained school where freshman Layfon Alseif has recently enrolled. Despite his initial reluctance, he joins the 17th Martial Arts Studies Unit under the leadership of third-year student Nina Antalk and embarks on an exciting journey filled with adventures. The story follows the reorganized version of the original novel, with Layfon serving as the main character.