The Atrable Federation, a powerful military force responsible for the ongoing Endless War, sets its sights on the Great Empire of Sun - a small island country with nothing but its name to boast about. This just so happens to be the homeland of the protagonist, Akiyama Maika (17), a girl in search of her father who left to fight when she was just a child. When the famed Ikkitousen-tai squad arrives in town, Maika sees an opportunity to inquire about her father's whereabouts, only to discover that he was not enlisted in the military. Disheartened and disillusioned with city life, she witnesses a large man falling from the sky - identified by onlookers as the Invincible Wolf, one of the members of the Ikkitousen-tai. He seems to have information about her father, but is unwilling to disclose anything to a civilian. Determined to uncover the truth, Maika decides to enlist in the unit, despite the military's ban on women. She is fierce and unwavering in her pursuit of her father, determined to uncover the secrets the Ikkitousen-tai are keeping from her.
