Atrable Federation is a military superpower that started the Endless War. After conquering many neighboring countries the Federation turns its attention to a small island country that is big only in name, the Great Empire of Sun.

Akiyama Maika is a girl seeking her father who went to war when she was little. Seeing the chance in the arrival of the legendary squad of mighty soldiers, Ikkitousentai, to a nearby city, she questions the military about her father's whereabouts. However, much to the girl's surprise her father appears not to be enlisted in the army. Maika, dejected by this news as well as savage city life, suddenly encounters a burly man falling from the sky. The bystanders name him the Invincible Wolf, one of the Ikkitousentai, and it seems like he knows something about Maika's father! Unfortunately, he isn't willing to tell anything to a civilian.

Maika decides to enlist in the Ikkitousentai in order to find her father. Even though the army doesn't accept women, such a thing won't stop Maika!