Koshu

Koshu (江朱, Kōshu) worked in Kokuboro's General Affairs Department. He has been serving Princess for over 300 years, and is both the designer and the administrator of the castle.

Appearance
Koshu's human form is a very short, black-haired man with glasses. His true form is that of a red octopus demon, and oddly enough, he stays the exact same size.

Personality
Koshu is a devoted follower of Princess, and is obsessed with the state and cleanliness of the castle, which he considers his.

Powers & Abilities
Koshu's only known power is flailing his tentacles, because in both the anime and manga, he is destroyed seconds after his transformation, without delivering a single successful attack or suffering any damage beforehand. In the anime, Tokine destroys him merely by collapsing a kekkai around him, and in the manga, Yoshimori does. This implies that he is no stronger than any of the nameless Kokuboro underlings that are brushed aside as Yoshimori, Tokine, and Heisuke Matsudo make their way through the castle.