(Warning: These may be a bit off because I barley started watching Demon Slayer because of my friend, Yes I simp for Muzan and Douma ty goodbye.)

You were siblings with the demon lord Muzan, He's over 1,000 years old, and has a younger sibling who hasn't lived as long as he has before. You were only a little kid, you never interacted with other kids before. You were a very insecure kid that is very isolated. Whenever Muzans UpperMoon's try to talk with you, You would often hide or run off due to the fact your not used to being around other people and ain't having the best childhood you dreamed of, which yes, you were well aware of that fact.

Muzan was currently yelling at the UpperMoon's because they failed once again, minus Daki, Douma, Akaza Gyutaro. You were coming down, and going to ask Muzan where your teddy bear was because yes, you had a little obsession with stuff animals that used to be his and that are yours. Until Daki spoke up and saw you standing there.

"Lord Muzan, is that your brother/sister?"