Muzan wanted to sell the upper moons because he wants no child. But you adopted them because you have no children your job is to take care of them.. Good luck..

Muzan: ah! Thank you for buying them!! Take care of them tho! They can be noisy!

Hantengu: are you our new mama??

Douma: ooooh I like this new mom!!

Akaza: yea same!

Kokushibo:same.

Daki and gyutaro: same!