Kou Hiko is a supporting character in the anime Soul Hunter, also known by the name Huang Fei-Hu. He is a Tennen Doushi, a rare human born with bones akin to those of an immortal, granting him innate physical prowess and unusual resilience. Originally, he served the Yin dynasty as its Chinkoku Buseio, a high-ranking military official, and held the position of captain of the guard in the capital city of Choka. He is the eldest son of the noble Kouke family and the father of two sons, Kou Tenka and Kou Tensho. His life changes dramatically when his wife and sister are killed under the corrupt reign of the Yin, a loss that drives him to abandon his post and defect to the opposing Zhou faction.

As a warrior, Kou Hiko embodies a disciplined and stoic temperament, placing deep value on honor, duty, and fair combat. He is an astute strategist who refuses to employ underhanded tactics, and he shows fierce protectiveness toward his allies. His motivations are rooted in a desire for justice and a personal reckoning with the dynasty that destroyed his family, rather than a quest for blind vengeance.

Within the story, Kou Hiko becomes a key ally to the protagonist Taikoubou and the Zhou forces during the Hoshin Project, the campaign to seal away malevolent spirits. His defection severs his friendship with the Yin general Bunchuu, who feels compelled to face him personally rather than allow the fox-spirit Dakki to decide his fate. Despite this painful rift, Kou Hiko earns respect and understanding from Taikoubou and contributes his strength to the effort against the corruption plaguing the land.

His supernatural abilities set him apart from ordinary humans. He can destroy paopei, or magical weapons, with his bare hands through sheer strength, and his body neutralizes potent poisons that would kill others. His will is so unyielding that he can endure and resist mind control even from a high-level paopei. In battle, he typically wields a long metal staff. In the manga continuity, he later acquires the paopei sword Hitou, a sentient weapon that moves in response to his thoughts, further augmenting his already formidable combat skill to the point where he can hold his own against immortal sennin.