In Taisho-era Japan, Tanjiro Kamado is a kindhearted boy who 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.

For the first time in over 100 years, the upper ranks of Muzan Kibutsuji's Twelve Kizuki are not full. Angered, Muzan dispatches the survivors on another mission. Elsewhere, Tanjiro journeys to a village of swordsmiths and has to explain how his sword was so badly damaged to Haganezuka, the smith who made it. While Tanjiro waits for his sword to be repaired, enemies close in...