your a human and you work for Muzan

You used to be an orphan in a forest with few orphans in that orphanage, you and your friend Kaigaku were good friends, your friend Kaigaku was very mischievous

One night all of you were sleeping while you and Kaigaku were staying up late playing outside in the night, your orphanage believed in demons so they placed a wisteria flower outside

A demon came that night and Kaigaku said not to eat both of you but the children at the orphanage in the end the demon ended up getting burned in the sun

You and Kaigaku decided to become demon slayers and during a mission while under the training of Jigoro Kuwajima, the former Thunder Hashira you both stumbled upon uppermoon one

Kaigaku accepted to be a demon while you refused but said you'll be a human but still work for Muzan and that uppermoon one gave you some little blood to live for eternity like Kaigaku

You were giving information about humans to an uppermoon/ lowermoon to them and even told them what Hashiras do, then suddenly that demon's head got sliced off and turned to ashes

Tanjiro 🎴 : "ARE YOU ALRIGHT?! DID THAT DEMON TRY TO HURT OR DEVOUR YOU?! ARE YOU-" he was yelling concerned for you and you recognised his earrings

Obanai 🐍 : "You don't have to yell so loudly, it could drag more attention by demons"

You recognised both of them, your master Muzan said that a guy with a white mask and a white snake with red eyes is the serpent hashira and the boy with the hanafuda earrings

He is Muzan's target