Kiyoko is the little sister of Inounoshishi. Her and Inounoshishi's father initially selected her to be the next Zodiac of the Boar for the 12th Zodiac War, but was manipulated and ultimately driven to suicide by Inounoshishi to acquire the title for herself.
Kiyoko is a young high school girl with red eyes and short, red hair that flares out at the ends. Like her sister, she also has a pair of tusks, and she has them at her temples.
Kiyoko initially comes off as an innocent young girl, but she has a sociopathic tendency and is shown to enjoy killing animals, even the babies, for fun. At school, she isn't any different and seems to have regular friendships as well as a possible boyfriend or love interest.
Kiyoko is the second heiress in the Boar Clan. It's heavily implied that she never had to take up the brutal training and abuse that her older sister had to, but even so, she was naturally drawn to killing.
Despite being the youngest of the two sisters of the Boar Clan, Kiyoko has little to no hesitation to kill, unlike Inounoshishi, even going as far as killing animals. This behavior is how her father decides she is fit to be the warrior to participate in the Zodiac War.
Distraught over being forced to learn how to kill and enduring years of her father's abuse for no reason, Inounoshishi becomes angered by this and creates a 12-year plot to pay it forward. She manipulates her sister into killing people, starting with her classmates, insisting that it was no different than killing animals. However, no matter how many times Kiyoko slaughtered lives, Inoushishi said it wasn't enough and persuaded her to continue. This treatment caused Kiyoko to spiral into madness to the point that she had to be detained in a cell until ultimately committing suicide after Inoushishi slid a knife to her. With her younger sister out of the way, Inoushishi took her place in the Zodiac War.
|The Twelve Eastern Zodiacs||Nezumi | Ushii | Tora | Usagi | Tatsumi Kyoudai Ani | Tatsumi Kyoudai Otouto | Uuma | Hitsujii | Sharyu | Niwatori | Dotsuku | Inounoshishi|
|The Twelve Western Zodiacs||Capricorn | Aquarius | Pisces | Aries | Taurus | Gemini | Cancer | Leo | Virgo | Libra | Scorpio | Sagittarius|
|Zodiac War Overseers||Duodecuple | Navi|
|Other||Inounoshishi's Father | Inounoshishi's Mother | Kiyoko | Head of the Niwa Clan | Head of the Dragon Clan | Head of the Snake Clan|