A steel monster named "Kabane" suddenly appeared in human society, causing great panic. Humans attacked by them will have the ability to come back to life and also begin to attack their own kind. Under the fierce attack of the monsters, human society soon fell apart, and the survivors built a fortress "post station" and survived by exchanging what they had with each other. The only means of transportation between the post stations is the armored steam locomotive. Ikoma (voiced by Yuu Hatakenaka) is a passionate young man who works in steam forging. He invented the weapon "Guantong" in the hope of contributing his own strength to the elimination of Kabane. By chance, Ikoma met a mysterious girl (voiced by Ayaka Senbongi). At the same time, a runaway incident caused the complete fall of the Xianjin Post Station where Ikoma lived. Kabane continued to be produced. Ikoma did not choose to escape, but took up arms and stood up.