As the world turned from the early modern to the modern time, Industrial Revolution began to engulf mankind all over the world. Out of the blue, an immortal monster appeared out of nowhere. The only way to defeat the monster is to physically destroy its heart, which is protected by steel tissues and skins. Once bitten by the monster, human die, then, revived and attacked other humans. The violent mobs, called Kabane, increased in numbers at an explosive rate. They kept spreading until they almost cover the entire world.
At a far east corner of the globe, in a country called Hinomoto, people built forts all over the place to protect themselves from the Kabane attacks. They called the structure station, and lived inside the station, while shutting down free transportation and commerce. It was all for survival. Only the official armed steam locomotive train (nicknamed Hayajiro) is allowed to transport between the stations. The residents of each station mostly sustained their lives by sharing what they produce through the train system.
The Aragane Station supports a large part of iron manufacturing and steam engine engineering. A young guy, named Ikoma, lives here as a steam engine ironsmith. He is working on a piercing device, which he calls “Tsuranukitsutsu” and expects to use it in the combat against Kabane someday. He’s looking forward to an opportunity in which his creation and ability proves to be a tremendous contribution to his community.
One day, Koutetsu Jou, one of the armed steam trains, rolls in to Aragane Station. Ikoma receives an assignment to help the cleaning and maintenance duty. There, he sees a mysterious young female who skips the required Kabane censorship.
That night, Ikoma meets with the same girl again. She calls herself Mumei. Unexpectedly, Hayajiro crushes into the Aragane Station. All of the crews on board turned into Kabane, which spilled to the station platform. Ikoma runs against the flow of panic-stricken crowds.
“I’m not going to run away this time… I will defeat Kabane, with my Tsuranukitsutsu!”
This is how Ikoma’s battle begins; A battle to become a truly outstanding man.