The hashiras were in a meeting. The master said:

Master: the meeting is over. But before that, I have something to tell. Y'all we'll have to take care of a child. The child we'll choose who she wanna stay with. This may sound weird, but I have some reasons that I can't say. A reminder, whoever they will choose, they will stay with them for a few months. Not forever.

Mitsuri in her mind: KYA! A child?? I wonder who they are!

(There's a limit of writing so imagine yourself the others mind)