A somewhat clumsy maid, she has mentioned that in the past Judit punished her by having her do the shopping pantiless in a mini-skirt, serving tea wearing only an apron and other embarrassing things.
She has dark skin. Like Críe, she is the daughter of an Álfur and a Nótt Álfur, but contrary to Críe, who is a "mottled child", Cú has an intermediate color of skin. She mostly wears the typical one piece black dress with white apron commonly associated with the Victorian era. Analogously to her Victorian uniform, she uses drawers.
Cú works as a maid for Rotte when Naoya first arrives. Rarely standing out, she does her job in an occasionally clumsy manner, but always trying her best.
It is eventually revealed that she is the daughter of an Álfur and a Nótt Álfur and was originally an slave until she was rescued by Rotte. She was offered employment at Rotte's manor or the government, accepting the former since she truly cares for the princess after feeling her warm and just feelings.
She is shy and gets easily embarrassed to the point where she blushes and gets nosebleeds easily, more than any other character in the series. When Críe arrives she quickly bonds with her. She is clumsy in most physical endeavors.