The synopsis for the film begins to tease itself as such, “Tanjiro Kamado – a boy ... to end the anime run with that secret 22 chapter final arc instead. Demon Slayer: Infinity Castle ...

Crunchyroll describes the anime film: Tanjiro Kamado – a boy who joined an organization ... is the demons' stronghold – the Infinity Castle. And so, the battleground is set as the final ...