In the early 20th century, a small republic found itself stuck between a kingdom and an empire - both of whom wanted to manipulate the republic to suit their own needs.

In order to protect itself from both sides of the conflict, the republic created a small group of soldiers whose job it is to suppress revolution and dissent in any way possible. This is the story of the Opera House.

Tanya Degurechaff is a reincarnated Japanese salesman-turned-sociopathic child soldier, forced by the almighty Being X to fight an endless war.

But soldiers need to eat, too. So join Tanya as she samples fine wartime meals.

A young girl fights on the frontlines in war. She has blonde hair, blue eyes, and nearly transparent white skin as she flies through the air and mercilessly strikes down her enemies. Her name is Tanya Degurechov and speaks with a young girl's lisp while she commands the army. Tanya used to be one of Japan's elite office workers, but because of a wrathful god was reborn as a little girl. Prioritizing optimization and career advancement above all, she will become the most dangerous entity among the Imperial Army's sorcerers.