Iki Sayuri is a young looking woman with brown shoulder length hair and light brown eyes. She is the mother of Hiyori and Masaomi Iki, and the wife of Takamasa Iki. Sayuri is portrayed to be quite old fashioned in both the anime and manga. As well as being melodramatic in personality, she holds all the traditional aspirations for her children--wanting Hiyori to find a good husband and have a family of her own. It is largely hinted that she would not approve of Hiyori's interest in wrestling, viewing it as "barbaric" and not acceptable for a young lady.
In chapter 54, it is revealed that her lineage allows the ability to sense and see denizens from the far shore. According to her mother, she is not able to see them--but she can feel their presence. This is hinted at in various parts of the manga; from sensing Yato in chapter 6 to speaking to Hiyori's spirit in chapter 49.