Kabaneri of the Iron Fortress: Battle of Unato (甲鉄城のカバネリ 〜海門決戦〜 Kōtetsujō no Kabaneri: Unato Kessen) is an anime movie set six months after the anime series. It was confirmed on March 8th, 2018 by Fuji TV. It was animated and produced by Wit Studio, picking up the story six months after the TV anime.
Ikoma and the Iron Fortress take their fight to the battlegrounds of Unato, joining the alliance to reclaim the region from the kabane horde.
Ikoma is temporarily confined after his violent kabaneri instincts take over. Without him, Mumei joins a team inspecting a possible kabane stronghold.
The alliance's mission ends in retreat but the fight continues. At the Castle, Ikoma and Mumei learn the truth about the force controlling the kabane.
- Direction: Araki Tetsurou
- Series Composition: Ookouchi Ichirou
- Animation Character Design: Ebara Yasuyuki
- Chief Animation Direction: Ebara Yasuyuki
- Music: Sawano Hiroyuki
- Animation Work: Wit Studio
- Hatanaka Tasuku as Ikoma
- Senbongi Sayaka as Mumei
- Uchida Maaya as Ayame Yomogawa
- Masuda Toshiki as Kurusu Konochi
- Satou Kensuke as Kibito
- Oki Kanae as Kajika
- Oosaka Ryouta as Sukari
- Ise Mariya as Yukina
- Maxwell Powers as Suzuki
- Miki Shin'ichirou as Kageyuki Komai
- Aida Rikako as Miyuki Komai
- Hanawa Eiji as Unmo
- Tezuka Hideaki as Kuroji
- Volcano Oota as Mogari
Mumei kills some Kabane protecting Koutetsujou while it passes an area full of the Kabane. A pipe breaks and she falls, but Ikoma catches her and they continue fighting the Kabane. Ikoma had given Mumei his green memento stone and asking her to keep it.
Miyuki was enjoying the snowing and didn't want to go inside where its warm. Her father Kageyuki then approaches her and puts another cloth on her to keep her from the cold. Later Kageyuki is seen injured in a battle, asking Unmo if he is human or kabane.
Six months after the fall of Kongoukaku, Hinomoto is split into several regions, each forced to fight against the Kabane. Continuing their journey Koutetsujou goes to Unato in Hokuriku to cross the mountain, which was overrun by Kabane five years ago and is impassable. Hokuriku Allied Forces are trying to recapture Unato, which has now become a battlefield. Koutetsujou joins the battle, clearing as many Kabane they can. As the soldiers have seen how Mumei fights, she admits she is a Kabaneri, but then she feels something and gets distracted and Ikoma comes to her rescue. Ikoma who had felt something too, realizes that the Kabane isn't acting mindless going for blood.
Kajika teaches Mumei how to knit and she was knitting a present to Ikoma as his hands may feel empty no longer having the stone. Kajika asks Mumei what he said when he gave her the stone and as she explains that he promised to turn her human, Kajika teases Mumei that was basically a marriage proposal, but embarrassed Mumei tries to deny it. On the next day, Mumei wants to give Ikoma the present, but he was in a hurry and tells her to do it later. Ikoma goes with Ayame to a meeting with the Kuroji army, Mogari army and Unmo from Unato, where they discuss their plan and the use of Narukami and Ikoma suggests they may get attacked from the rear, from the territories they had taken already and wants to go to investigate, as he believes someone is controlling the Kabane. Ikoma then feels something again and doesn't feel well. Kuroji comments that he isn't fit in a war council and Ayame apologizes for his behavior.
Ikoma plans on heading alone to investigate, but Mumei tries to stop him, which makes him think she also don't believe him. He have trouble controlling his blood lust and attacks Mumei, who is willing to let Ikoma bite her, as he won't be able to keep his promise on turning them human. Ikoma regains control and stops himself, but gets arrested and isolated for three days. Ayame is distracted worrying about Ikoma, and if she the right thing. Kurusu explains that while he doesn't know what Ikoma sees, he was never wrong at who their enemy is, which made Ayame start believing in Ikoma. Unmo reveals that there are underground tunnels made by Kageyuki and the group realizes that Ikoma was right. They go to investigate and find a secret passage covered by Kabane's metal membrane.
Meanwhile, Kuroji decides to begin the Narukami campaign early due to the warmer weather. But as Narukami moves closer to the castle, the Kabane burst out of the secret passage and start attacking the soldiers. Mumei decides to go and the defeat the one controlling the Kabane and enters the secret passage. Learning about Mumei, Ikoma breaks free and goes after her. Narukami makes its first shot at the castle, but the castle membrane is too hard to break. They prepare a second shot, but a mysterious man standing on top of the castle, shoots blood at Narukami. A horde of Kabane then rushes and attacks Narukami, overheating and destroying its main gun. Kuroji attempts to use the hayajiro and escape, but Kabane rush inside of it, killing him and derailing the hayajiro.
Mumei had avoided series of traps and eventually encounters a powerful and fast Wazatori, who easily overpowers her. As he is exhausted and about to be crushed to death, Ikoma arrives and kills the Wazatori.
Ikoma arrives, killing the Wazatori and saving Mumei. Ikoma heavily injured and exhausted tells Mumei that he haven't forgotten their promise and wants she to stay by his side forever. As they embrace, a mysterious green light surrounds them and heals them. Sukari's crew manages to find them and they advance along the tunnel. Meanwhile, Mogari decides to retreat as Narukami campaign failed, but Ayama persuades him, making him join her in order to not look like a coward in her eyes. Together they drive Koutetsujou upwards towards the castle.
Ikoma's group reach the castle's tower and see a child in Kabane cocoon with blue light. As they get shot at, Unmo realizes this is Kageyuki, the previous lord of the castle. He explains that fire years ago he fought with them, and had strangled himself returning back to life as Kabaneri, but as the soldiers were too afraid of him being a Kabane, they turned on him. His daughter, Miyuki tried protecting him and got shot. Kageyuki then proceeded and killed all the men and then bit his daughter, wanting to revive her even if its as Kabane. Mumei explains that Miyuki had become the heart of a Fused Colony that will soon burst and try to destroy everything.
Unmo tries to reason with Kageyuki, but Ikoma saves him from Kageyuki's gun shot. That gave Mumei a chance to shoot and make Kageyuki drops his gun. As he went to pick it up, Mumei manages to catch up to him and they start fighting. As bullet ricochets on Miyuki's cocoon, Mumei sees an illusion of Miyuki and Kageyuki. Unmo gets in front of Kageyuki, letting him stab him with his blade on the gun, but Kageyuki tells him its too late and he lost his future because he hesitated to tell the soldiers he was human and not Kabane, and then stabs Unmo again. Seeing he gave his heart to the hatred, Mumei regains her conviction and fights Kageyuki, managing to fatally shoot him. Witnessing her father death, Miyuki cries and transforms into a Black Fog, emerging from the mountain.
Ikoma's group returns to Koutetsujou and they try to run away, but the Black Fog manages to grab the train and get on top of it. Yukina speeds up the train into a dead-end tunnel and as they enter it, the train's cannon fire, hitting the Black Fog, causing it to hit the tunnel, destroying it and causing it to burst. A blue light snow then starts falling, in his dying moments, Kageyuki sees the snow and comments its the last snow of the year.
Koutetsujou leaves Unato and continues their journey. Ikoma recalls something Takumi had told him, which he thinks that hhe understands now and that the Kabane hate towards the humans had spread over Unato and was making them anxious. He reconfirms to Mumei that he haven't forgotten his promise and she asks him if he is wearing her present. She tricks him into believing the pattern on the stone moves and as he stares to see it, she sneaks a kiss surprising him and then she feels really embarrassed.
- https://kabaneri.com/ Official Japanese website]