Youjo Senki

A ruthlessly efficient salaryman dies after challenging the mysterious Being X and awakens in another world as Tanya Degurechaff, a young girl growing up in an empire surrounded by war. Gifted with extraordinary magical ability and retaining the mind of her former life, Tanya enters the military hoping that perfect performance will earn her a safe career far from the front.

The plan backfires spectacularly. Her tactical brilliance, terrifying discipline, and willingness to exploit military logic make superiors see an ideal officer, repeatedly sending her toward the most dangerous battles. As the Empire slides into a wider world war, Tanya rises through the ranks while fighting enemies, bureaucracy, and Being X itself in a stubborn attempt to secure the peaceful life she believes she deserves.