The destruction caused by the Mugen Train disaster continues to weigh heavily on the Demon Slayer Corps' members. Despite being allowed time to heal, life must carry on: a nasty monster is harassing the lovely ladies of the Yoshiwara Entertainment District. Tengen Uzui, the Sound Pillar, and his three wives are on the case. Tengen, however, fears the worst when he loses touch with his spouses and enlists the assistance of Tanjirou Kamado, Zenitsu Agatsuma, and Inosuke Hashibira to infiltrate the district's most prestigious households and discover the wicked Upper Rank demon.