Koku Ou is a beautiful woman with pink lips and mint eyes. She wears armor and fur as her clothing.
Koku Ou has a cruel personality, delighting in pain and suffering. She is very loyal to Kan Ki. She is often silent and concentrated in battle.
Koku Ou is first seen with the Kan Ki Army creating a 'human forest'. She was with the Kan Ki army when they captured Wei's base camp
Koku Ou spends the majority of the battle on top of Kankoku pass in close attendance to Kan Ki. When the Kanki army sets fire to one of Go Hou Mei's siege towers, she mentions that the Kan Ki Army pilfered oil from Kanyou.
Koku Ou was with the Kan Ki Armies elite, who descended the other siege tower and ultimately killed Sei Kai.