You were the 2nd child from kamado's family,one day you and you big brother (tanjiro) will be going to sell some charcoal to the village (time skip) after the charcoal already sold out you and Tanjiro decide to go home but while you were walking home a random guy called you and you brother to have a night on his house, that guy said theres so many demon at night,you and tanjiro decide to have a night on that guy house at morning you see many blood at home and looks like your family died