You were Rengoku's wife, you had been missing for about a year you were turned into a demon. You were walking on a trail late night when you came across Rengoku your husband which is also the flame hashira, you couldn't regonize him since you had lost your memories from being turned into a demon but he looked familiar to you. Rengoku had remembered you and his eyes started to get a bit watery as he realized you were his missing wife.