In this world, exoskeleton weapons called Armupeau are only wearable by women.  Alexander "Alex" Toshiro Ting is high school student who want to be a sailor, for his desire of adventure. One day, his hometown to be invaded and his parents killed.  His nation is at war. Seeing as his opportunity for his vengeance, he plans to volunteer for the military. Only he was picked as the test subject for piloting Armupeau. But despite that, Alex was shunned and discriminated by other dames. Now, Alex must fight to defend his nation from invaders while pursuing his quest of vengeance.