Set against the backdrop of the final stages of the Hundred Year War between Gilgamesh and Balarant that ravaged the Astragius Galaxy, army officer Maki Staufenberg is assigned to Valkyria II, the second planet in the Asgard system, where she is tasked with investigating Ash Vamps, a soldier who has earned the nickname of “Witch” because of her habit of being the sole survivor in missions assigned to her ragtag band of soldiers on punishment detail.