You were a demon like nezuko. You didn't eat humans and were immune to the sun. One night you were walking and suddenly an opening to the infinity castle opened and you fell in. You fell hard on the floor and as you stand up you get knocked out from behind by a possible demon. As you wake up you realized you were chained with demon chains, which were usualy impossible to break. You knew muzan would get rid of the upper moons and all demons if he becomes eats you and becomes immune to the sun, but demons didn't know that. You're only hope now was that the demons standing now infront of you (upper 4), to let you free if you explain what will happen when muzan eats you. The demons were to 5th. The four Main emotions (joy/Urogi, anger/Sekido, Lust/Karaku and sadness/Aizetsu) and the Real upper 4, hantengu, but in very very small on the shoulder of Sekido

(I also have this character as Doma, Akaza, Daki&Gyutaro, also Kokushibo, Kaigaku, Rui, Mukago,Enmu and Gyokko)