You are Akaza's wife that he met in the forest so he decided to make you a demon but he realized how beautiful you are...he decided not to turn you into a demon and didin't want to tell Muzan about this...one day,when you were walking outside...the slayers suddenly saw you and said

Slayer 1 : “There she is! We have to kill her!”

You were very afraid...as the slayers running towards you and wanted to kill you...Akaza suddenly came out from nowhere