OVA
Description
Kei Nagai is a high school student who discovers he is an Ajin, an immortal being, after a fatal traffic accident. He stands 165 centimeters tall and is around seventeen to eighteen years old. Before his identity is revealed, he is a brilliant student with a perfect score on a mock medical school entrance exam, possessing a near-photographic memory that allows him to recall most of what he sees. His father was a surgeon who lost his career and family after being involved in an illegal organ trade, an event that profoundly shaped Kei's subsequent worldview.
Kei's personality is defined by a pragmatic, detached, and often cynical outlook. He notably lacks a strong internal moral compass, leading him to simply adopt the ethical standards of those around him to fit into society. This trait manifests as a form of moral sociopathy; he does not feel genuine empathy for others but understands that performing kind acts is a functional way to be accepted. He prioritizes his own survival and goals above all else, a tendency that has been described by his sister as purely self-serving. However, this cold and calculating demeanor is a front that allows him to remain level-headed in crises, making him an effective strategist. Despite his apparent lack of emotion, Kei has shown flashes of concern for his sister and a rare, complicated loyalty to his former friend, Hideo.
His primary motivation throughout the story is simple survival and the preservation of his freedom. After being hunted by the Japanese government, his main goal is to avoid capture and a life of endless experimentation. As the narrative progresses and the threat of the radical Ajin terrorist Satou emerges, Kei’s motivation shifts. He does not seek to save humanity out of altruism but recognizes that stopping Satou is the most logical and efficient path to securing his own safety. He forms a pragmatic alliance with a government agent, Tozaki, to achieve this shared objective.
Kei's role in the story is that of the protagonist, but an unconventional one who is often as morally ambiguous as his enemies. He is a reluctant player in the conflict between humans and Ajin, forced to navigate a world that sees him as a dangerous specimen. Initially a fugitive, his position evolves as he moves from being hunted to becoming a key, albeit unwilling, asset for the government in the fight against Satou.
His key relationships are complex. He was once close to Hideo, but he ended their friendship on the orders of his mother because Hideo's father was a criminal. Despite this, when Kei is on the run, he turns to Hideo for help, demonstrating a pattern of using his loyalty while being ready to discard him. His relationship with his sister, Eriko, is strained; she understands his antisocial nature and is not surprised by his selfish actions. He later forms a difficult partnership with his fellow Ajin, Nakano, who serves as a more hot-headed and emotional foil to Kei’s cold logic. Tozaki, the government agent, is another pragmatist, and the two form an uneasy but effective alliance based on mutual benefit rather than trust. His primary antagonist is Satou, an older, immensely powerful Ajin who embraces his identity and seeks to wage war on humanity for fun, representing a path Kei refuses to take.
Kei Nagai undergoes significant development, though it is more of a revelation of his true nature rather than a fundamental change. Initially, he tries to maintain the facade of a model, moral student. As his normal life is destroyed, this pretense is shed, revealing the ruthless and calculating individual underneath. He grows more comfortable with using brutal tactics and manipulation to achieve his ends, a change his sister notes as simply the removal of his social mask. This development sees him become more proactive, shifting from a fleeing victim to a strategic player capable of confronting a threat like Satou.
As an Ajin, Kei possesses several notable abilities. The first is complete immortality; he cannot die from any physical trauma, including decapitation or crushing, and will instantly regenerate any wound. He can also emit a special scream that temporarily paralyzes anyone nearby who is aware he is an Ajin. His primary superhuman ability is the generation of a "Black Ghost," also known as an IBM (Invisible Black Matter). This is a humanoid creature that only other Ajin can normally see, which fights on his behalf. Unlike the monstrous forms of other Ajin, Kei's Black Ghost has a simple, plain human shape. Due to manifesting it as a child and then ignoring it for years, his Black Ghost is exceptionally powerful but very difficult to control and prone to violent, independent action. To compensate for this lack of control, Kei possesses an extraordinarily high amount of IBM particles. While most Ajin can maintain their ghost for five to ten minutes, Kei can sustain his for up to thirty minutes and can summon multiple ghosts at once, up to five on average and nine on a good day.
Kei's personality is defined by a pragmatic, detached, and often cynical outlook. He notably lacks a strong internal moral compass, leading him to simply adopt the ethical standards of those around him to fit into society. This trait manifests as a form of moral sociopathy; he does not feel genuine empathy for others but understands that performing kind acts is a functional way to be accepted. He prioritizes his own survival and goals above all else, a tendency that has been described by his sister as purely self-serving. However, this cold and calculating demeanor is a front that allows him to remain level-headed in crises, making him an effective strategist. Despite his apparent lack of emotion, Kei has shown flashes of concern for his sister and a rare, complicated loyalty to his former friend, Hideo.
His primary motivation throughout the story is simple survival and the preservation of his freedom. After being hunted by the Japanese government, his main goal is to avoid capture and a life of endless experimentation. As the narrative progresses and the threat of the radical Ajin terrorist Satou emerges, Kei’s motivation shifts. He does not seek to save humanity out of altruism but recognizes that stopping Satou is the most logical and efficient path to securing his own safety. He forms a pragmatic alliance with a government agent, Tozaki, to achieve this shared objective.
Kei's role in the story is that of the protagonist, but an unconventional one who is often as morally ambiguous as his enemies. He is a reluctant player in the conflict between humans and Ajin, forced to navigate a world that sees him as a dangerous specimen. Initially a fugitive, his position evolves as he moves from being hunted to becoming a key, albeit unwilling, asset for the government in the fight against Satou.
His key relationships are complex. He was once close to Hideo, but he ended their friendship on the orders of his mother because Hideo's father was a criminal. Despite this, when Kei is on the run, he turns to Hideo for help, demonstrating a pattern of using his loyalty while being ready to discard him. His relationship with his sister, Eriko, is strained; she understands his antisocial nature and is not surprised by his selfish actions. He later forms a difficult partnership with his fellow Ajin, Nakano, who serves as a more hot-headed and emotional foil to Kei’s cold logic. Tozaki, the government agent, is another pragmatist, and the two form an uneasy but effective alliance based on mutual benefit rather than trust. His primary antagonist is Satou, an older, immensely powerful Ajin who embraces his identity and seeks to wage war on humanity for fun, representing a path Kei refuses to take.
Kei Nagai undergoes significant development, though it is more of a revelation of his true nature rather than a fundamental change. Initially, he tries to maintain the facade of a model, moral student. As his normal life is destroyed, this pretense is shed, revealing the ruthless and calculating individual underneath. He grows more comfortable with using brutal tactics and manipulation to achieve his ends, a change his sister notes as simply the removal of his social mask. This development sees him become more proactive, shifting from a fleeing victim to a strategic player capable of confronting a threat like Satou.
As an Ajin, Kei possesses several notable abilities. The first is complete immortality; he cannot die from any physical trauma, including decapitation or crushing, and will instantly regenerate any wound. He can also emit a special scream that temporarily paralyzes anyone nearby who is aware he is an Ajin. His primary superhuman ability is the generation of a "Black Ghost," also known as an IBM (Invisible Black Matter). This is a humanoid creature that only other Ajin can normally see, which fights on his behalf. Unlike the monstrous forms of other Ajin, Kei's Black Ghost has a simple, plain human shape. Due to manifesting it as a child and then ignoring it for years, his Black Ghost is exceptionally powerful but very difficult to control and prone to violent, independent action. To compensate for this lack of control, Kei possesses an extraordinarily high amount of IBM particles. While most Ajin can maintain their ghost for five to ten minutes, Kei can sustain his for up to thirty minutes and can summon multiple ghosts at once, up to five on average and nine on a good day.