Weeping

Stunned by how quickly Tengen overcame Daki, Tanjiro is reminded by the Sound Hashira that the battle continues, since his sibling remains wildly out of control. He strains to hold Nezuko down as Tengen advises singing a lullaby to lull her to sleep. Just then she finds her footing and leaps out a window, dragging her brother along as the struggle goes on. Realizing his words cannot reach her, Tanjiro pleads silently to his mother for guidance, then recalls the earlier suggestion and begins a song their mother once sang.

At first nothing changes, but the melody slowly gets through. Remembering how she had asked their mother about the tune as a child, Nezuko bursts into tears, comes back to herself, reverts from her swollen demonic shape to her usual childlike form, and drifts off to sleep. Relieved, Tanjiro cradles her in his lap.

Inside the house, Daki shrieks at Tengen for taking her head, and he coldly tells her to die in silence. Furious, she throws a fit over his refusal to grant her Upper Rank standing, which he confirms, even as she keeps insisting on it. To his amazement she begins bawling, and he observes she has babbled far too long for someone who ought to be dying. Still sobbing, she cries out for Gyutaro to rescue her, and a male demon starts rising from her body. Sensing the threat, Tengen swings at once, but his blades meet only air as the pair vanish. Behind him, Gyutaro soothes Daki, urging her to reattach her own head and heal her burn while praising her looks, then wounds Tengen when he attacks again. Commending both the assault and the block, Gyutaro reveals he had meant the blow to be fatal and chillingly readies himself for combat.

• Tanjiro's lullaby soothes Nezuko back to sleep and restores her human form.
• A second demon, Gyutaro, emerges from Daki's body.
• Gyutaro lands a wound on Tengen and prepares to fight.

This is the 85th chapter, part of the Entertainment District Arc and compiled in Volume 10. Episode 40 of the anime corresponds to these scenes.