鋼殻のレギオス

In a future where pollution-born creatures called contaminoids have overrun most of the land, what's left of humanity survives inside mobile fortress-cities known as Regios. Layfon Alseif transfers into the academy city of Zuellni and is talked into its 17th military arts platoon, led by third-year student Nina Antalk, alongside Felli Loss, Sharnid Elipton and Harley Sutton. Layfon keeps quiet about the past that made him one of the strongest fighters in his old city, and about why he left it behind.