"Panzer fräulein ALTESEISEN" is a manga series set in a world where humanity faces constant threats from mysterious mechanical beings known as "Eisen." These creatures emerge from the depths of the earth, wreaking havoc and endangering human civilization. To combat this existential threat, humanity develops advanced armored suits called "Panzer," which are piloted by young women known as "Panzer Fräulein." These pilots are chosen for their unique compatibility with the Panzer technology, which grants them extraordinary combat abilities.

The story centers on Alteseisen, a young girl who becomes one of the Panzer Fräulein after her village is destroyed by the Eisen. She is paired with a highly advanced and experimental Panzer unit, which sets her apart from other pilots. As Alteseisen trains and fights alongside her fellow Panzer Fräulein, she uncovers secrets about the origins of the Eisen and the true purpose of the Panzer technology. The narrative explores themes of survival, sacrifice, and the moral complexities of warfare, as Alteseisen grapples with her role in the conflict and the personal losses she endures.

Key characters include Alteseisen, whose determination and resilience drive the story forward; her commanding officer, who provides guidance and strategic insight; and her fellow Panzer Fräulein, each with distinct personalities and combat styles. The series also introduces enigmatic figures from the Eisen side, hinting at a deeper connection between the mechanical beings and humanity. As the battles intensify, alliances are tested, and the line between friend and foe becomes increasingly blurred. The manga balances intense action sequences with moments of introspection, delving into the psychological toll of war on its young protagonists.