A mysterious virus appears during the Industrial Revolution that transforms infected humans into Kabane (かばね, "Corpses") and rapidly spreads.

Kabane are aggressive, undead creatures that cannot be defeated unless the glowing golden heart, which is protected by a layer of iron, is pierced, or an important body part (such as the head) is completely severed.

A young engineer called Ikoma uses the opportunity to test with success his anti-kabane weapon, the "Piercing Gun" (ツラヌキ筒, Tsuranuki Zutsu), but is infected in the process, although he manages to resist the virus and become a Kabaneri (かばね人), a human-kabane hybrid.

Assisted by Mūmei (無名, "Nameless"), another Kabaneri who appears to help them, Ikoma and the other survivors of the station board a hayajirō named Kōtetsujō (甲鉄城, lit.

Kabaneri of the Iron Fortress was directed by Tetsurō Araki and written by Ichirō Ōkouchi,[15] with music by Hiroyuki Sawano and original character designs by Haruhiko Mikimoto.

[40][41] Episode 1 The story begins with a retelling of the TV Series focusing on events leading to the Kōtetsujō travelling to the town of Unato.

Ayame and Kurusu with Ikoma hold a meeting with Kuroji of the Federal Forces, General Mogari of the Echigo-Tora-Ohuki and Unmo representing the Unato population.

Kuroji plans to use the Narukami, an armored hayajiro with giant cannon mounted on board, to blast the castle while Mogari's men and 200 Unato fighters led by Unmo lead a ground assault.

Episode 2 Ikoma prepares to investigate the Unato Kabane, but he has trouble controlling his blood lust and attacks Mumei, so he is arrested.

Meanwhile, the Narukami reaches the main route to Unato early so Kuroji decides to begin the assault on the castle immediately.

"Kabaneri of the Iron Fortress -Revolt- Beginning Tracks") was released on December 19, 2018, for Android and iOS, featuring an animated opening sequence by Wit Studio.