Cruelty

Living quietly in the mountains, Tanjiro Kamado supports his widowed mother and younger siblings by selling charcoal in the nearby town. As the new year approaches, he heads down to make his rounds, parting from his mother, Nezuko, and the little ones. His unusually sharp nose makes him popular with the villagers, and one even relies on it to clear up a household dispute.

Because nightfall is unsafe, an old man named Saburo persuades him to stay over rather than climb the mountain after dark, warning that demons prey on travelers. Tanjiro returns home the next morning to a horrifying sight: his home is wrecked and his family lies dead. Only Nezuko retains any warmth, so he hoists her onto his back and rushes for help.

On the way she awakens transformed, attacking him with fangs and growing strength. Tanjiro manages to reach what is left of her heart, and she stops to weep. A passing swordsman, Giyu Tomioka, moves to behead the demon, but the siblings' refusal to harm one another convinces him to spare her instead. He directs Tanjiro toward a teacher named Sakonji Urokodaki before leaving.

A demon murders the entire Kamado household while Tanjiro is away overnight, leaving only Nezuko alive.

Nezuko, infected by demon blood, transforms and turns on her brother before regaining a measure of her humanity.

Giyu Tomioka, a member of the Demon Slayer Corps, decides not to kill Nezuko after witnessing her protect Tanjiro, and points the pair toward Sakonji Urokodaki.

This chapter belongs to the Final Selection Arc and appears in Volume 1. It was adapted as the first episode of the anime. Giyu's instruction to keep Nezuko out of sunlight and to seek out his old mentor establishes the path Tanjiro follows for much of the series.