In an epic confrontation, Tanjiro and his fellow Demon Slayers have fought on through the night, suffering terrible losses against the King of Demons, Muzan Kibutsuji. Dawn is breaking soon, and if they can keep Muzan at bay just a little longer, it will be the end of the centuries-long struggle. But Muzan, who will stop at nothing to destroy the Demon Slayers, unleashes his most terrible powers. If he can't defeat the Demon Slayers, he may be able to cause them to destroy themselves from within. All fates and destinies will be decided as the sun begins to rise...

In Taisho-era Japan, kindhearted Tanjiro Kamado makes a living selling charcoal. But his peaceful life is shattered when a demon slaughters his entire family. His little sister Nezuko is the only survivor, but she has been transformed into a demon herself! Tanjiro sets out on a dangerous journey to find a way to return his sister to normal and destroy the demon who ruined his life.