Will Demon Slayer Infinity Castle movie show Kokushibo's final fight? Explored

Demon Slayer Infinity Castle is already shaping up to be one of the most ambitious anime film projects of all time, and fans can’t stop speculating about how the trilogy will unfold.

With the first film already released in Japan, the buzz has only grown louder about which battles will make it to the big screen and which will be saved for later. Among these, Kokushibo’s climactic final fight stands out as one of the most anticipated moments in the entire story.

But will the Infinity Castle movies actually show it? Or will his battle with the Demon Slayer Corps be reserved for the second or even third installment of this epic finale?

The first Demon Slayer Infinity Castle movie focused heavily on Akaza’s fight against Tanjiro and Giyu, along with Shinobu and Kanao’s battle against Dōma. So, will Demon Slayer Infinity Castle show Kokushibo’s final fight? All signs point to yes in Part 2 of the trilogy.

Unlike earlier arcs that focused on one major demon, the Infinity Castle arc is a battlefield where multiple fights happen at once, testing every Hashira to their absolute limit. From Shinobu’s tragic showdown with Doma, to Zenitsu’s long-awaited duel with Kaigaku, to Giyu and Tanjiro teaming up against Akaza, the arc is packed with jaw-dropping moments.

And yet, the battle everyone circles back to is the ultimate clash with Kokushibo, Upper Moon One. As the strongest of Muzan’s demons besides Muzan himself, Kokushibo embodies centuries of power and represents the peak challenge before the final confrontation.

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The case for Kokushibo in Demon Slayer Infinity Castle Part 2

Many fans believe Kokushibo’s final fight will headline the second Demon Slayer Infinity Castle movie. Here’s why:

1. Narrative Flow: Demon Slayer Infinity Castle Part 1 gave Akaza and Dōma their spotlight. To keep momentum, Part 2 needs to escalate the stakes. Kokushibo naturally serves as the “semi-final boss” before the grand showdown with Muzan.
2. Length of the Fight: Kokushibo’s battle is long and involves multiple major characters. Compressing it into the third movie alongside Muzan’s fight would risk rushing both. Giving it a full movie ensures it receives the attention it deserves.
3. Emotional Weight: Part 1 already delivered heartbreak with Shinobu’s sacrifice and Akaza’s tragic past. Part 2 could double down on emotional devastation with the deaths of certain Hashira during Kokushibo’s fight, priming audiences for the final movie’s cathartic victory over Muzan.

If this is Ufotable’s strategy, Part 2 would balance Inosuke and Kanao finishing off Doma’s arc, Zenitsu’s fight against Kaigaku, and the colossal clash against Kokushibo. That lineup alone is blockbuster material.

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Release date information: Demon Slayer: Infinity Castle movie

Demon Slayer Infinity Castle was initially released in Japan, where it became a massive hit. It will soon premiere worldwide, and fans can refer to this list to book tickets at their nearest cinema:

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Fan reactions and expectations

Even before Demon Slayer Infinity Castle Part 1 premiered, fans on Reddit and Twitter were speculating about Kokushibo’s place in the trilogy. Many agree that his fight will be “the movie that breaks the box office” because of the sheer hype surrounding it.

Some are already comparing it to the Tengen vs. Gyutaro fight from the Entertainment District arc, saying Kokushibo’s battle could eclipse it in both scale and animation. Others worry about pacing, with some pointing out that Part 1 already felt a little bloated with flashbacks.

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Final thoughts

Beyond spectacle, Kokushibo’s fight is thematically crucial. He represents what could have happened to the Demon Slayers if they gave in to despair and sought strength at any cost. His centuries-long existence as a corrupted swordsman makes him a dark mirror to both Tanjiro and the Hashira. Without Kokushibo’s arc, the narrative would lose much of its emotional and philosophical weight.