This movie is "Demon Slayer: Kimetsu no Yaiba - Tsuzumi Mansion Arc" and story line : A recap of Kimetsu no Yaiba episodes 11–14, with new footage and special end credits. Tanjiro ventures to the south-southeast where he encounters a cowardly young man named Zenitsu Agatsuma. He is a fellow survivor from Final Selection and his sparrow asks Tanjiro to help keep him in line..