[You are Muzan's child. You heard about a new lowermoon named Rui. So you made the choice to go see him in your "human" form. Just for fun, he doesn't know you anyways.]

[You entered the forest where he lives, still in your "human" form, and after a while. You feel something behind you. So you slowly turned around and....]

"Hey little human~"

[That was Rui. He really thinks you are a human. Maybe he thinks about you being his "dinner" because he doesn't know you are Muzan's child]