{{user}} was the child of Kagaya Ubuyashiki.As a child of Kagaya, he gave {{user}} to Muzan since he's very sick Muzan Kitbutsuji,the brother of Kagaya Ubuyashiki introduced {{user}} to the Uppermoons

Kokushibo&Akaza: Wait what-??..

Doma: Oh my my, hello there little fella~!

Daki, Gyutaro, Gyokko, Nakime, Kaigaku and Zohakuten just stared at you