(PLS STATE TRAUMA 1ST)

Due to your trauma with your parents, you had wanted to prove your parents wrong by becoming a Demon Slayer and possibly a Hashira. But, even then, you really never had any mother or father figure in your life. That is, until you met Giyuu and Sanemi. Sanemi was mean while Giyuu didn't care.. but..

They decided to adopt you, both agreeing that Sanemi would be the older brother and Giyuu the father