Anime fans thought that Kabaneri of the Iron Fortress Season 2 was in the cards for 2018, but it seems Wit Studio has other plans. Instead of announcing Koutetsujou no Kabaneri Season 2, the official website for the series has revealed a trailer video for a Kabaneri of the Iron Fortress movie called Koutetsujou no Kabaneri: Unato Kessen (Kabaneri of the Iron Fortress: Unato Decisive Battle). But the announcement also hinted that another volume is planned for the series, which could mean a second season or another movie sequel.
Technically, the new Koutetsujou no Kabaneri movie is the third film in the series. The first two films were compilation movies that covered the events of the first anime season that aired in 2016. At one time, fans could watch the English sub version by streaming episodes on the now-defunct Amazon Anime Strike, but the license expired. Funimation eventually rolled out the English dub, but it's only available via Blu-ray/DVD, not Crunchyroll or Funimation Now.
Affectionately known as the "steampunk zombie train anime" by some fans, the story has humanity hiding in train stations from the threat of the Kabane, which are like zombies with steel hearts. These feudal fortresses are connected only by heavily armored trains called Hayajiro and slowly the Kabane have been overwhelming humanity. The main character, Ikoma, vows to stop the Kabane, but when he becomes infected during an attack he ironically transforms into a Kabaneri, a human whose mind is still in control of an infected body.
The story is similar to Attack on Titan largely because the original story was created by director Tetsuro Araki and Wit Studio, the team responsible for Attack on Titan. The creator of Code Geass, Ichiro Okouchi, wrote the screenplay. According to Mantan Web, director Araki said he still had feelings for the main character after finishing the second compilation movie and wanted to create a direct continuation of the story. The new movie will be a sequel, not a spin-off, that is set six months after the ending of the first season.
What is interesting is that the official website lists the new movie as the "middle volume" in the series. That admission could mean that Kabaneri of the Iron Fortress Season 2 is still possible in the future, although it could just mean a fourth movie is already being planned for the future. From a financial perspective, it makes sense for Production IG and Wit Studio to focus on developing the franchise since they own it outright.