Just Hang On There (Muichiro X Reader)

"But....what if I don't see you as my sister?"

Muichiro only listens to you, his step sister. He doesn't remember anyone, but he never forgets you, and never will.

You, having earth breathing and being the earth hashira, take care of muichiro tokito as your brother. Despite all the responsibilities as the hashira, yn manages to carry out her responsibility as a guardian for him. But, little did she know, he doesn't see her in that way. But what does he think of her? Even he, himself doesn't know. But through out all the ups and downs, yn manages to always be with muichiro. Trying to find the cure for him to regain his memory. And after him and yn have been poisoned by the demon lord, himself, yn still doesn't step back in life and starts working on different antidotes after having trained to be a medical hashira too. But, the girl who has always been stuck with her brother throughout her life-after joining the demon slayer, her life completely changes. Although muichiro doesn't tend to interact with anyone other than yn. Yn gets many people with whom she goes through the cleverness of life. Trying to find Muzan Kibutsuji and curing her brother. Will she succeed?