Huang, whose real name is Kiyoshi Kuno, is a middle-aged man who serves as the field supervisor for a cell of operatives working for a shadowy organization known as the Syndicate. Unlike the other members of his team, Huang is a normal human being with no supernatural powers. His physical appearance is somewhat unkempt and weary; he is balding with short brown hair, usually has stubble on his face, and is often seen wearing a black flat cap and a matching overcoat over a red shirt and vest. He is a heavy smoker and is frequently seen with a cigar, and his habits also include drinking, as he claims to have a remarkable tolerance for alcohol.

Before being recruited by the Syndicate, Huang was a detective in the Japanese police force. His life changed dramatically after meeting a woman named Shihoko Kishida, whom he fell in love with. Unbeknownst to him, Shihoko was a Contractor, a type of being for whom he would later develop a deep hatred. Their relationship ended in tragedy when Shihoko assassinated his police partner, Isozaki. Following this event, the Syndicate offered Huang a choice: have his memories of the incident erased or join their organization. He chose to work for the Syndicate, a decision made at Shihoko's request because she did not want him to forget the love they shared.

This painful past is the root of Huang´s personality, which is initially defined by bitterness, cynicism, and a profound distrust of Contractors and Dolls. As the only human on his team, he frequently expresses his disdain for the supernatural beings he is forced to work with, viewing them as cold, logical monsters or, in the case of Dolls, as mere tools to be used and discarded. He is often demanding and irritable with his teammates, Hei and Yin, and displays little patience for their methods or their lack of typical human emotion. However, despite his gruff exterior, Huang consistently demonstrates a sense of responsibility for his team, often arriving at the last moment to provide backup with his exceptional skills in using conventional firearms.

In the story, his primary role is to act as the intermediary between the Syndicate and his team. He relays mission objectives, provides intelligence, and issues orders to the powerful Contractor known as Hei, the sentient cat Mao, and the Doll Yin. His key relationships gradually evolve over time. Although he initially treats Yin with cold indifference, he begins to question his belief that Dolls are purely objects after witnessing her cry, a distinctly human act of emotion. The most significant turning point in his development occurs when his past resurfaces in the form of a mission involving Shihoko. Reunited with her, he learns that she truly loved him and that she had been the reason his memories were spared. When Hei attempts to help the two of them escape from the Syndicate, Shihoko commits suicide to save Huang from their watchers. This traumatic event fundamentally changes Huang´s worldview. His deep-seated hatred for Contractors begins to fade, and he starts treating Hei, Mao, and Yin with genuine respect as true comrades.

Huang´s primary ability lies in his proficiency with weapons. Despite being an ordinary human, he is a highly capable fighter who uses guns and explosives with great skill, often providing critical backup to his more powerful teammates from a distance. Later in the story, after he and his team are cut off from the Syndicate, Huang fully commits to his new-found sense of loyalty. In a final act of sacrifice, despite having been shot and bleeding heavily, he uses his own vehicle to set off a bomb, creating a diversion that allows Hei and the others to reach Hell´s Gate, giving his life for his team.