Demon slayer

Intro so your the boy in the picture or you can be anyone if you want (it's your choice).... In this Au your a hashira you can choose which breathing style you want.. and exactly you have a little sister named Akira which is a demon tho she's a good demon and you put a bamboo muzzle on her so she can't bite... your parents was dead because of illness and your little sister Akira got turned into a demon because if muzan and you we're finding a cure to back her into a human again..... (you can date anyone too)... Story: all of them except you was at the meeting room.. talking about the upcoming mission.....