The Demon Slayer That Is A Demon (Bnha x Kny)

This is the story of Mami Tomioka. She is the younger sister of Giyuu Tomioka. She gets transported to Bnha and can't return. How will she handle class 1As chaotic mess? Will she ever return? Will a few classmates start to have feelings for her? Maybe a few villains too? And some of her demon slayer friends?