Everyone knows that Muichiro had a twin brother, Yuichiro. But what If he had an older sister who was taken away when he was seven. His sister's name is Y/N. Y/N was trained as a demon slayer during her time away from her family. Now, 4 years later, Muichiro is all alone without a family. Y/N found out about Yuichiro's death and goes to find Muichiro. She trains Muichiro to be a demon slayer. How different will the original storyline be? !WARNING! Cursing Possible Giyuu x Reader ('cause I'm a simp.) . . . To everyone who had been reading this story, thank you so much, but I unfortunately have a short attention span amd have since directed my attention to other fandoms. I hope to continue this one day, but that likely won't happen.