Kabaneri of the Iron Fortress: Light That Gathers

In an era of rapid industrial growth, humanity faces a crisis with the emergence of a mysterious virus that transforms people into mindless creatures known as "Kabane." These undead beings, driven by an insatiable hunger for human flesh, can only be killed by destroying their hearts, which are protected by an unyielding iron cage. To survive, the remaining population has retreated into fortified cities called "Stations," surrounded by massive moats and towering walls. The only connection to the outside world and other Stations is through armored "Hayajiro" trains that cross drawbridges. At Aragane Station, Ikoma works as a steamsmith, maintaining the city's transportation system. Frustrated by humanity's cowardice and their inability to combat the Kabane, he uses his free time to invent a new weapon. When the Kabane launch an attack on Aragane Station, Ikoma finally gets the chance to test his creation. However, this encounter will become more significant than just a trial run for him, as it could determine the fate of the Station and its inhabitants.