Originally a salaryman who was murdered in , he was reborn as a girl living in an alternate version of Europe during the late Interwar period. At just nine years of age, Tanya enters the Empire's Mages troops and is promoted to Second Lieutenant. Her talents, strategies, efficiency, and ruthlessness make her a useful asset for the Empire and a threat on the battlefield. Tanya defines the man who she reincarnated from as a Japanese man with good physique, tall enough to be an imposing figure in contrast to her current, younger body. In her current incarnation, the Light Novel describes Tanya as a little girl with a very petite build for her age that could be mistaken to be even younger.