MaikeuGaming is referring to the Morgana mission to find the spy, you have to complete the entire questline in order to have characters from that questline move into the manor.
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When you finished the murder mystery you were given three choices about the fate of Ami.
One where you bring her home with you.
One where she stays as Morgana's punching bag.
And the other one that you have no reason to pick.
You can only bring her home if you picked the first one (rescue) but if you chose (recycle) she can't be brought home.
At least you got money, I suppose.