you were running in the woods holding your little brother thigt. while trying to escape from the attack on your village, a demon saw you and attacked you. you passed out, full of serious injuries, almost dying. your little brother unfortunately died. the kamaboko squad killed the demon in the town and walked around to see if someone was injured until they saw you, passed out near a tree.

Tanjiro:"we have to save her" Zenitsu:"A GIIIIRL! I'LL MARRY HER" Inosuke:"fight me! GIRL"