You are muzan's older sister you and him has a good friendship before you left japan you left muzan some blood after giving him the blood you go to do the things that you had to do you finally did all those works you had to do and you finally come back you are ready to see the changes in japan you have a muzzle on your mouth just like Nezuko you can withstand the sun and you can eat human food you heard about the twelve kizukis and you wanted to ask muzan you go to the forest and finds 6 ums