Sound Hashira Tengen Uzui

The thirty-fourth anime episode, the eighth of season two, follows the aftermath of the Mugen Train mission as the survivors recover at the Butterfly Mansion. Tanjiro travels to the Rengoku residence to deliver Kyojuro's final message, where he clashes with the grieving and embittered Shinjuro. Four months later the Sound Hashira, Tengen Uzui, arrives and presses Tanjiro and his friends into a new assignment. This double-length installment runs roughly forty-six minutes.

News of Rengoku's death reaches both the Corps and his family, devastating his younger brother Senjuro. Elsewhere Akaza reports to Muzan, who is disguised as a human child, that he has failed to locate the Blue Spider Lily but has slain a Hashira. Far from pleased, Muzan tortures and dismisses him, scolding him for taking a wound from a non-Hashira swordsman. Alone afterward, Akaza shatters Tanjiro's dropped Nichirin sword and vows to remember his face.

Following Rengoku's crow, Tanjiro reaches the Rengoku home and meets Shinjuro, the former Flame Hashira, now drunk and dismissive of his late son. When Shinjuro spots Tanjiro's earrings he reacts with fury, identifying him as a user of Sun Breathing and explaining that it is the original technique from which all others derive. A brief fight ends with Tanjiro headbutting him. Senjuro later gives Tanjiro the past Flame Hashira's records, only for them to discover the relevant pages torn out, and presses his brother's sword guard upon the visitor.

Months pass as the three young slayers train. Tanjiro, now fighting alongside the recognized Nezuko, defeats a Mantis Demon with Water Breathing. Returning home, he finds Tengen Uzui forcibly carrying off Aoi and Naho. Kanao intervenes, Tanjiro confronts the Hashira, and after a tense standoff the boys volunteer to accompany him. Tengen reveals their destination: the Entertainment District of Yoshiwara, where a demon is hiding.

Three of the eyecatchers recreate the covers of the corresponding manga chapters. The episode runs at double length. The manga has Akaza shatter the sword within the courtyard of the false family residence Muzan occupies, while the anime moves the scene to a lone forest. The adaptation also adds an entirely new sequence in which Tanjiro and Nezuko battle a mantis-like demon shortly before Tengen's arrival, a fight that the manga only mentions in passing.