A high school student, Mamoru Nakajima, was rescued by a girl wearing an aircraft wing and engine when she was involved in a passenger plane accident during a school trip and was falling. The girl calls her guardian "Type 0 fighter type 21". It was a world where weapons with a girl's mind and body lived! For some reason, the weapon girls shouldn't leave the guards with the ability to supply and repair! ?? A different world story where you live and fight together with weapon girls!