Youjo Senki: Apoptosis

Lieutenant Colonel Tanya Degurechaff was once Japan's elite salaryman. Yet, due to a feud with Being X she was forced to reincarnate in a world of constant warfare. However, her life was about to change when she successfully applied for a transfer into the Gestapo. As she met a mysterious detainee suspected to be part of the Emperor's assassination, her life started to change.