The Hashira, Sanemi and Iguro, along with their comrades head to an abandoned castle on top of a mountain for a mission, while Tanjiro is being treated at the Butterfly Mansion for the wounds he suffered at the Swordsmith Village. Later on, the Hashira gather at the Ubuyashiki Mansion to hold a Hashira meeting, where Muichiro reveals how the marks manifested. In an effort to strengthen the entire Demon Slayer Corps from the bottom up, the Hashira Training begins...
Along with looking into the changes to Nezuko,
we want you to collaborate with her.
إضافة إلى البحث في التّغيّرات الّتي طرأت
.لنيزوكو، نودّ منك التّعاون معها أيضًا
Wir möchten Sie für eine
Forschungskooperation gewinnen,
Quisiéramos que investigaran juntas,
incluyendo los cambios en Nezuko.
Me gustaría que investigaras
los cambios de Nezuko con ella.
Accepteriez-vous d’étudier ensemble
les changements survenus chez Nezuko ?
Vorremmo studiassi insieme a lei
Gostaríamos que investigasse ao 
lado dela as mudanças na Nezuko.
Вам стоит работать вместе.
ซึ่งก็รวมถึงเรื่องการกลายร่างของเนซึโกะด้วย