Tanjiro, Zenitsu, and Inosuke go on their first mission together and venture to Mount Natagumo. Too afraid to go up the "spooky mountain" with Tanjiro and Inosuke, Zenitsu stays behind. Tanjiro and Inosuke encounter a mountain laced with spider webs and controlled by Spider Demons. These Demons have already dispatched countless Demon Slayers, forcing Kagaya to send in the Hashira as reinforcements.