Gyuutarou’s auto-destruct causes a huge explosion, but Tanjirou survives, and Lil’ Nezuko wakes up to purge the poison from his body with her Blood Demon Art. She then puts the immobile Tanjirou on her tiny back and dashes him across the ruins of the district, eventually coming upon Zenitsu and Inousuke, whom she also heals.
Finally, Nezuko and Tanjirou find Uzui and his wives, who are bickering with each other rather than hearing the final words he has to say. But before any of them know it, Nezuko has sidled up and envelops him in her pink flames. The wives have no idea what is happening, but when Uzui’s poison wounds vanish and he pulls through, they envelop him in hugs and sobs of relief.
Nezuko and Tanjirou then search for the heads of Gyuutarou and Daki, and find them still alive, bickering with each other over their loss to the humans as their heads slowly dissolve. When their argument escalades into saying they aren’t brother and sister, Tanjirou intervenes, saying that even if the entire world is against them, they shouldn’t be against each other; not in these final moments.
Daki then directs her ire at Tanjirou for lecturing them, but an in-depth flashback narrated by Gyuutarou shows that Tanjirou was quite correct. Long before he became a demon, Gyuutarou was cursed for being an extra mouth to feed in the poorest part of the district. When his sister, whose original name was Ume, was born, he leaned into his ugliness, found his strength, and found work as a debt collector.
Sadly, once Ume turned thirteen she joined a run-down house where her body could be sold, and the defiant nature Gyuutarou baked into her backfired. She took the eye of a samurai she didn’t want to sleep with, and was bound and burned alive while Gyuutarou was out on a job. When he grieves over her body, he’s cut down by that same samurai, but not deeply enough, and Gyuutarou in turn kills the samurai and madam.
Gyuutarou always cursed the fact that for all of the misfortune he and Ume had to deal with, the world never once cut them a break and allowed them any good fortune. The nearest thing to providence came in the form of the former Upper Six, who gave Gyuutarou and Ume blood to drink, turning them into demons. Gyuutarou never regretted being one, but did regret that Ume could never live the life she should have. We see heartbreaking glimpses of that possible life.
Now in the void between worlds, Gyuutarou doesn’t want Ume to follow him any more, and is very mean about it, telling her to go in the opposite direction, towards the light, where perhaps she might be resurrected and have another chance at that possible life of comfort and fortune. But Ume won’t go that way. She pounces on Gyuutarou from behind and reminds him of his promise: they’d always be together. She’d rather follow him into the deepest darkness than step into the light alone.
While I’m usually not a fan of filling in character backstory after they’ve already met their fate, the postmortem backstory of Gyuutarou and Daki/Ume had ample emotional resonance, and gave this finale a quieter, calmer, yet still powerful rhythm, winding down the bombastic battle of previous weeks.
All’s well that ends well, with Uzui planning to retire and spend more time with his lovely wives, confident that Tanjirou is about to reach Hashira-worthy potential. Tanjirou, Nezuko, Inousuke, and Zenitsu also share a tearful group hug, reunited and in (mostly) one piece. Yet I’m sure Tanjirou’s joy is tempered by the “there but the grace of god go us” vibe from a brother-sister pair who weren’t as lucky as they are.
So ends the Entertainment Arc, where most other Winter shows have only hit their halfway point. What’s next for Demon Slayer? No official announcement follows end credits—an extended arrangement of the rippin’ good Aimer opening theme—but I can say with certainty the Demon Slayer anime will return (Update: it will!).