Koku'Ou is a formidable female general in the Kan Ki Army of the Qin state. She serves as the leader of her own clan of bandits that make up a contingent of Kan Ki's forces. First introduced as a 5000-Man Commander, she was later promoted to the rank of General prior to the Battle of Eikyuu. She deeply admires Kan Ki for his leadership and personal qualities. Her personality is rough and harsh, but she possesses exceptional intuition and maintains a calm, analytical eye on the battlefield, allowing her to assess situations effectively. She is a highly skilled archer and is known to be strict and particular about the men she allows into her inner circle.

Her role in the story is that of a loyal and capable lieutenant of Kan Ki. She was first seen during the Koku You Campaign, participating in Kan Ki's unorthodox and brutal tactics, including the creation of a human forest to terrorize the enemy. In that campaign, she demonstrated her martial strength by easily pushing back enemy forces. During the Gyou Campaign, she took part in the Battle of Gian and successfully escaped the chaotic retreat alongside the other surviving commanders of Kan Ki's army. At the Battle of Eikyuu, she was appointed as the first general of Kan Ki's central army. Despite the overwhelming defeat of Kan Ki's forces at the hands of Riboku's Zhao army, she displayed her survival instincts and tactical awareness by escaping the encirclement.

Her key relationships are primarily defined by her unwavering loyalty to Kan Ki. She fights alongside other major commanders within the army, such as Rai Do and Zenou, who each lead their own bandit clans. Her development is marked by her steady rise in the ranks, demonstrating that her intuition and command ability are valued highly enough to entrust her with a general's position during a critical campaign. Her core abilities lie in her archery, her calm strategic intuition, and her leadership of her clan warriors.