It's kind of similar to the anime Promise Neverland! The adults use kids
And its set in like historical time!!
Summary
Faceless shadow nobles living in a vast mansion, attended by living dolls who spend much of their time cleaning up the soot endlessly emitted by their mysterious masters.
Follow the story of Emilyko, a young and cheerful living doll, as she learns her duties serving as the attendant for Kate Shadow-sama.
There's a anime of it as well under the similar name
Yeah shadow House has an anime too!
If you see this it's your sign to read Shadow House!! PLSSSS READ SHADOW HOUSE ITS A MASTERPIECE PLSPLS THE ONLY THING LACKING ABOUT SHADOW HOUSE IS IT FANBASE!!!