Different (Tanjiro X Kocho's sister! Reader)

(Y/n) Kocho is Kanae's and Shinobu's biological younger sister who's roughly around the same age as Kanao, her adoptive sister. They both attend the same final selection to join the Demon Slayer's Corps and that's when it all started. Tanjiro and (Y/n)'s fate intertwined but how will it go on from there? Warning: THIS...