You're Gonna Have A Bad Time
In the time since Muzan's defeat, the demons across Japan faded as well. This lead to the Demon Slaying Corps seeing many of its members leave and seek out a peaceful life as civilians. However that did not spell the end of the Demon Slaying Corps as volunteers, including the last generation of Pillars consisting of the men and women who survived the final battle against Muzan, remained in the Demon Slaying Corps to keep the peace. While initially, the new head of the Ubuyashiki family, Kiriya Ubuyashiki, thought that it would be a long time before their services would be needed, a string of coordinated attacks by a new generation of demons and humans ravaged the countryside and convinced Kiriya otherwise. Due to this revelation, Kiriya has assembled every available and willing Demon Slayer to the Ubuyashiki Manor for an emergency meeting to discuss their plans to end this threat swiftly.