The Pillars and You 3

They are in the blacksmith village and you go with Muichiro and Mitsuri as well as you meet Tanjiro and Genya (Sanemi's younger brother) (You wear a black hood that does not let you see your clothes or something while also a mask that covers your face)
Nobody knows you and much less Muichiro because your parents sacrificed themselves for you when you were children so in this au your parents died against the demon it's not like in the original story
You attack with your katana but your katana contains wisteria poison even though you have the ability to cut heads but the wisteria poison is stronger than the knives with wisteria poison that you always carry
You are the same height (1.60) and age (14 years) as Muichiro
Your breathing is solar, that of the nightmare, that of darkness, all the breathings and if you like, invent some as you wish, you are a higher rank than that of the pillars, very little known for being one of the most difficult to achieve.
You wear a black haori with mint stripes like the one in the picture and Muichiro wears a white haori with mint stripes while their hair reaches their hips and they both look like girls.
You continue to have amnesia while Muichiro regains his memory
Ships:
Invent ships with others
Yuichiro x Sanemi
Sanemi likes you just like in the other parts