TV-Series
Description
Kô Nakano is a young ajin who becomes a key ally in the effort to stop Satô. He is of average height and build, with short light brown hair, reddish-brown eyes, and notably thick dark eyebrows. His most common attire is a t-shirt or hoodie with jeans.

Nakano came from a troubled home. He describes his parents as good-for-nothing and neglectful; they would often leave him alone at home to go out and enjoy themselves. This upbringing left him feeling unwanted and uncertain about his own worth. After someone took him in and gave him work, he developed a strong personal code: if there is someone out there who relies on him, he will do whatever it takes to be there for that person.

He is highly emotional, impulsive, and possesses a strong sense of justice. He is very considerate of others, showing genuine concern for the safety of his companions. Unlike Kei Nagai, who is cold, pragmatic, and often detached, Nakano wears his heart on his sleeve and believes in fighting for people who have helped him. He is also somewhat clumsy and often unaware of the bigger picture, preferring to improvise rather than rely on strategic planning, which means he depends heavily on Kei for tactical direction.

His primary motivation is to stop Satô, who plans to commit mass murder in order to create an ajin-led government. Nakano values human life and cannot accept the loss of innocent people, a stance that puts him at odds with Kei's more utilitarian logic. After escaping from Satô's gathering of ajin, he seeks out Kei and eventually convinces him to join the fight. He later works as part of Yû Tosaki's team, fighting alongside Izumi Shimomura and Kei.

His key relationship is with Kei Nagai, who serves as his foil. Where Kei is calculating and indifferent, Nakano is emotional and caring. Their clashing worldviews lead to frequent arguments, yet they eventually learn to work together, and Kei later helps Nakano unlock his ability to summon his IBM. He also develops a close friendship with Izumi Shimomura, expressing concern for her safety and training alongside her.

Throughout the story, Nakano grows from a frightened fugitive into a brave, if still reckless, soldier. He finds his place in a conflict where he initially lacks the supernatural powers of his peers, learning to rely on his physical strength, determination, and growing resolve.

His most defining trait is that he cannot initially summon his IBM, also known as a black ghost. This makes him rely on physical combat and his immortality to contribute. Like all ajin, he possesses the ability to regenerate from any fatal wound upon death. He also has a paralyzing scream that can freeze people in place when he shouts. He is athletic, has good reflexes, and is capable of sensing danger, such as evading tranquilizer darts. Although he cannot summon his IBM at first, it does manifest later, appearing as an incomplete, somewhat weak form. A recurring irony is his fear of heights, yet his most common cause of death is falling from high places.