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.

After centuries of preparation and training, the Demon Slayer Corps has come face-to-face with their greatest enemy, Muzan Kibutsuji. It is a desperate battle, and several Demon Slayers have already been killed. Tanjiro himself has engaged Muzan. Despite giving it everything he has, Tanjiro gets taken out of the fight! But although he is severely injured and near death, he sees a vision of his ancestor that may hold the key to finally destroying Muzan!