A family is attacked by demons and only two members survive - Tanjiro and his sister Nezuko, who is turning into a demon slowly. Tanjiro sets out to become a demon slayer to avenge his family and cure his sister.
Hari and Duri are a sister and brother living in the Shinbi apartment complex, which is more than a hundred years old. Living with them is a 102-year-old goblin named Shinbi.