At some point in the past, Chou Kou joined the royal harem as a eunuch, serving directly under the queen Mother as her closest adviser and bodyguard. It is unknown for how long he has held this position, but it must be long enough to gain the Queen Mother's complete trust.
Chou Kou is praised as a genius by the Queen Mother and would have been the youngest to rise to the position of chancellor if he were not a eunuch. He alone laid down the groundwork for creating the state of Ai.
Apart from his political virtues, Chou Kou also has sharp instincts and complete awareness of the environment around him. He also quite the skilled swordsman.