|Birthdate||June 5th, 1989|
|First Appearance||Shikigami no Shiro|
|Role||Protagonist, Supporting character|
Sayo Yuuki (結城 小夜 Yuuki Sayo) is a major character in the Shikigami no Shiro series. She appears as a playable character in Shikigami no Shiro and Shikigami no Shiro II. In Shikigami no Shiro III, she however, died and merged with Kohtaro Kuga's shikigami, Sazae.
In the games were she was playable, her normal attack was to fire an series of multi-directional cards, with the middle rows becoming red during High Tension. Her shikigami attack is to swing her Phoenix around her, while her bomb was a screen-kill attack.
- Sayo seems to have a relation to Anolegos Dundeon from Shikigami no Shiro II.
- Shikou Mibuya is her uncle.
- She needs to be near Kohtaro Kuga in Shikigami no Shiro III for energy and sustenance.
- She despises Fumiko Odette Van Stein.
- She easily becomes very jealous.
A Shinto shrine maiden with designs on Kohtaro. Sayo appears to be investigating the murders at the request of another. She attacks with spiritual wards.
A shrine maiden from a strong religious home, she has never gone to school due to her upbringing. The new incidents have caused her to leave by train, and come to Tokyo. Sayo's special still consists of a Phoenix familiar. It can either attack in a wide, slow radius(shown) or with a narrower(and faster) one.
Sayo Yuuki has taken the place of the deceased Sazae as Kohtaro Kuga's Shikigami, to save her own life. While Sayo's new look is the result of her taking Sazae's role, she can also be used with her original appearance from the earlier games.
|Protagonists||Kohtaro Kuga · Sayo Yuuki · Gennojo Hyuga · Fumiko Odette Van Stein (Chibi) · Kim Dae-jeong · Niigi Gorgeous Blue · Roger Sasuke · Emilio Stanburke · Batu Harai · Mihee Kim · Reika Kirishima · Nagino Ise · Munchausen · Tagami|
|Supporting Characters||Sazae · Neko · Moonsong · Devourer · Strider|
|Antagonists||Aku Miyoko · Juu Fujishima · Aku Hiroshi · Aku Bauman · Shoujo · Arala Cran · Anolegos Dundeon · Ajo Brothers · Yukari Horiguchi · Shintaro Kuga · Shikou Mibuya · Freedom Wind · Kagachi · Tsukiko Johjima|