Voir Demon Slayer: Kimetsu no Yaiba (Original Japanese Version), Season 1 - Episode 23

Ubuyashiki, the head of the Demon Slayer Corps, finally appears before Tanjiro. While Ubuyashiki reveals that he’d like to accept Tanjiro and Nezuko to join the corps, the Hashira are unable to accept this decision right away. Then, the Wind Hashira, Sanemi Shinazugawa, slashes his own arm and taunts Nezuko with his blood, trying to draw out her true colors as a demon.