What kind of title is this?: Manga.
Where can I read it?: Reading links are listed for Official Site, Yen Press, Shonen Jump Plus, Naver Series. Check availability in your region.

Synopsis

About Shadows House

In the depths of a murky mansion lives a group of enigmatic nobles known as...the Shadow family. With no visible features to speak of, these mysterious aristocrats employ living dolls to act as their “faces.” Kate and Emilico are one such pair of mistress and servant, dwelling in their own little world and learning from each other bit by bit with every new day. But in a house of locked doors, living according to rules from no apparent source—how long can their blissfully peaceful existence truly last...? (Source: Yen Press)

Fantasy Horror Mystery Slice of Life Supernatural