Sakae Ashiya is the father of Hanae Ashiya and a former secret employee of the Mononokean. He had been missing for years and is currently presumed to be either dead or a spirit of some sort.

Sakae has golden hair and eyes, though it is unknown as to whether his colouring came through the use of dye and contacts.

His hair was of medium-length, reaching the nape of his neck and was either loose or half-up. He is commonly seen in a school uniform.