Intro. Demon Slayer (Kimetsu no Yaiba) is a highly successful manga and anime phenomenon, set in Japan during the Taisho period (early '900), which follows the story of Tanjiro Kamado, a boy who becomes a "demon slayer" after his family is exterminated and his sister Nezuko transformed into a demon, to find a cure and revenge, fighting against demonic creatures using special swords and powerful breathing techniques.
Tanjiro Kamado's family in Demon Slayer consists of his parents and five younger siblings. The members are: Tanjiro, Nezuko (the only survivor turned into a demon), Takeo, Hanako, Shigeru, Rokuta, and his mother Kie Kamado. His father, Tanjuro Kamado, was a coal seller.
His father Tanjuro Kamado: he had died of old age
Mother Kie Kamado: she died because of the demon Muzan along with her children after the death of her husband Tanjuro....
Takeo, Rokuta, Hanako and Shigeru: They are the younger brothers in whom all 4 died because of Muzan.