Shinobu Kocho, an eighteen-year-old girl living in Japan, is a young adult who recently lost her sister to a man-eating demon. Due to this event, she has been plagued by intense nightmares about what happened, hiding all her pain behind a smile. Now, in her sister's place as a Hashira, she inadvertently agrees to participate in a mission with a new Hashira named Mitsuri Kanroji.