Akira is a boy born into a family of eight aristocrats who control the country with the power of spirits more powerful than ordinary people. However, for some reason, Akira does not possess a spirit. After being banished from his birthplace, Akira runs away to another state and joins a unit that exterminates incarnations. Gradually, her peculiar constitution, which is revealed to be able to create powerful spells and repel miasma (a miasma that causes noxious gas), catches the attention of the spell-user's union and a female swordsman from a powerful noble family. In addition, the ritual that Akira reluctantly undergoes in order to be promoted awakens "the thing that truly blesses" her. But at the same time, a huge monster is awakening that will engulf the city...!