In the Taisho Era of Japan (1912-1926), a scientist named Ayanokoji invented the Steel Angel, a humanoid with superhuman physical abilities. The Imperial Army saw potential in the creation as a new weapon of modern warfare, but for Ayanokoji, it was a step forward in the future of humanity. Against army orders, he secretly created the Steel Angel, called Kurumi. One day, young Nakahito Kagura snuck into Ayanokoji's home as part of a dare from his friends, and stumbled upon Kurumi's seemingly lifeless figure. The house was suddenly attacked by the Imperial Army, causing Kurumi to fall on top of Nakahito, where their lips met. In a moment that started a miracle, Kurumi woke up.