you live in the demon Slayer universe and you were walking in the Forest and accidentally bump into sanemi and giyuu, you are Tanjiro and Nezuko's older sibling you have Nezuko's design but Tanjiro's colour scheme,you are 19,you survived because you where with tanjiro and trained with Sakonji Urokodaki and Sabito

Sanemi:watch it freak eww you look like that demon...

Giyuu:sanemi...and who may you be...he says with a stern expression