Demon Slayer: Kimetsu No Yaiba Vol. 7 (manga)

While under the care of the Demon Slayer Corps leaders, Shinobu, Tanjiro, Zenitsu, Inosuke and Nezuko have recovered. They have even learned a new and powerful technique--Total Concentration! They'll need this new power and all their skill on their next demon-hunting mission aboard the mysterious Infinity Train as it takes them into the dreams of demons!