Swordsman Accompanying a Demon

Episode 6, adapting Chapters 10 and 11, follows Tanjiro on his debut Corps assignment. Before he leaves Mount Sagiri, Sakonji Urokodaki tells him about the gear he now carries: a uniform woven from a special fiber that resists water, flame, and the bite of a lesser demon, and a fresh box of lighter, hardier wood for transporting Nezuko by day. The episode introduces the Swamp Demon, the first proper enemy Tanjiro hunts on his own, and it ends just as Nezuko leaps into the fight.

The northern town

Reaching the town to the northwest, Tanjiro meets Kazumi, a distraught man whose partner Satoko vanished without a trace. While the locals have written off the disappearances, Tanjiro tells Kazumi he believes him and starts investigating, picking up the lingering trace of a demon in the alley where Satoko was last seen.

The swamp creature appears

That night a girl named Tokie is dragged through her own bedroom floor as it turns to dark, swampy water. Tanjiro races across the rooftops, drives his blade into the ground, and pulls her free from the muck. He realizes the demon wields a Blood Demon Art and that he is actually facing three identical copies of it.

Nezuko steps in

Tanjiro recalls Sakonji's warning about the progenitor Muzan Kibutsuji, the original demon from over a thousand years ago. As the clones overwhelm him, Nezuko bursts from her box, kicks one aside, and gently touches Kazumi and the girl, seeing her own siblings in them before charging the demons.

The two eyecatchers reproduce the covers of Chapters 10 and 11. The opening differs from the manga: the printed version begins with Tanjiro already in town, while the anime adds a short scene of him donning the uniform and receiving Sakonji's briefing, material the manga presented only as a memory. Muzan appears here as a silhouette during Sakonji's explanation.