After years of her persistent lack of faith, God, or as Tanya calls him, Being X, finally decides to let her die so he can banish her to the deepest pit of hell he has. However, something goes wrong, and Tanya ends up in a new world, filled with Demon Lords and Monsters. With a whole new world to get her grasps on, this devil turned Demon now has to adapt and overcome.
In the aftermath of Tanya's Death and the Empire's defeat, the nation now finds itself divided between Ostania and Westalis, both locked in a localized cold war of espionage against the other. Now an orphan as well as the only mage left with mana, Tanya seeks a strong education to rise up and live a stable peaceful life.