Ep. 21: Rui remembers his past and Tanjiro faces the Hashira after the battle.
Aired on August 24, 2019

As Rui dies, he recalls his frail human life and how Kibutsuji made him a demon. He killed his parents, realizing too late their genuine love, and suppressed these memories. Tanjiro senses Rui's grief and offers comfort as the demon fades. Giyū stops Shinobu from striking Nezuko, recognizing the siblings from two years ago. He tells Tanjiro to flee while he blocks Shinobu, who warns against Corps rules. Kanao Tsuyuri kicks Tanjiro and attacks Nezuko, but Kasugai crows order everyone to stand down for custody. Inosuke reflects on his weakness, while Zenitsu and other victims are treated by the Kakushis. The sun rises, and Tanjiro awakens bound before the Hashiras.
Episodes
- Ep. 17 · A subordinate of Muzan Kibutsuji is nearby after Tanjiro defeats the Mother Spider Demon
- Ep. 18 · Giyu and Shinobu arrive at Mount Natagumo while Tanjiro and Inosuke battle Father and Rui.
- Ep. 19 · Water Hashira Giyu Tomioka defeats the Father Spider Demon on Mt. Natagumo
- Ep. 20 · Tanjiro and Giyū defeat Rui while Shinobu kills the Daughter to save Murata
- Ep. 21 · Rui remembers his past and Tanjiro faces the Hashira after the battle.
- Ep. 22 · Tanjiro Faces Trial Before the Hashira Regarding Nezuko's Demon Status
- Ep. 23 · Tanjiro and Nezuko depart for Butterfly Manor after proving their worth to the Hashira.
- Ep. 24 · Tanjiro and Inosuke begin rehabilitation training at Shinobu Kocho's residence
- Ep. 25 · Tanjiro practices breathing techniques during rehabilitation at the Butterfly Mansion