Ajin (亜人, Demi-Human) are the titular species of the series. Ajin look exactly like normal people, with the only things separating them from other humans being the fact they can generate Invisible Black Matter, or IBM, within their bodies, making them immortal.
Seventeen years before the beginning of the series, the Ajin were first discovered in Africa, when a soldier fighting on the battlefields rose from the dead countless times. This earned him the name "Soldier of God (神の兵 Kami no Hei?)", and he soon became famous throughout the country he was fighting in. When word got out, an American government organization captured him and confirmed his immortality. While they tried to suppress this information from the public, it was simply too big, and it quickly became public knowledge.
There is no known method to discern Ajin from humans apart from them dying and reviving. However, it's possible for one Ajin to discover another Ajin if that person sees their IBM. It's also possible for Ajin to make their Black Ghost visible to humans when Ajin feel extreme emotions such as rage and bloodlust.
Abilities and Powers
The defining trait of all Ajin is their immortality. They are unable to die under any circumstances, such as being completely crushed, decapitated, or even due to malnutrition. The exact mechanism of this is unknown but Ikuya Ogura suggested that the only way it is possible would be because they possess an unknown matter in their body which replaces any body tissues or nutrients lost.
An Ajin's wounds begin healing immediately after a revival and it only takes a few seconds. However, they only begin to heal after dying, or "resetting", otherwise their injuries will not heal immediately and will only heal at a natural rate. This resetting doesn't heal physical deformities that the user was born with, however, as shown in Okuyama's case. This reinforced the statement that Ajin always return to their original state, even if that state is not 100% functional.
An Ajin passively uses the largest piece of flesh as a base and collects the smaller pieces for regeneration. However, pieces that are too far away are not collected and instead replaced by growing new body parts. The leftover piece will then simply stop working. Notably, an Ajin can regenerate from a severed body part, no matter how far the location of that severed part is from the rest, but only if that body part is the largest part remaining of their body. For example, if their entire being is completely destroyed, a severed piece of their arm that is removed from their body 100 meters away, they can regenerate their entire being from that arm.
There is technically one way for an Ajin to die, though it depends on ones definition of death. As previously mentioned, and Ajin regenerates from their largest piece and leftover pieces that were severed will simply stop working. If an Ajin's head is chopped off and too far away to reattach itself, a new head will grow it's place. The new head will have all the memories and personality of the original, but technically the old head will have “died”. The old head will still be conscious of what is going on for a few moments. This is the closest known way an Ajin can come to death, although it has been theorized that an Ajin may be able to die due to complications of old age.
Ajin can also use a paralyzing scream that seizes the nervous system, paralyzing everyone in their immediate vicinity (its range is still unknown). Researchers think that this is a type of thanatosis reflex, which is why it works better on people who don't know about Ajin. Its effects on the targeted person can also be neutralized by the user if he/she wishes to (as in the case of Nagai and Kaito). However, this ability can be easily countered by simply wearing ear plugs or some other kind of noise dampeners.
Invisible Black Matter
- Main article: Invisible Black Matter
Theorised by Ogura to be the main cause of the Ajin's powers, all Ajin shown so far possess Invisible Black Matter (インビジブルブラックマター Inbijiburu Burakku Matā?) which cannot be seen by normal humans. This matter is what allows the Ajin to replace any lost body tissues or nutrients, but there is a more lethal way in which it can be used. Created using the IBM, a Black Ghost (黒い幽霊 Kuroi Yūrei) is a humanoid entity which is manifested by an Ajin and most commonly used for combat purposes. However, it should be noted that not all Ajin are able to materialize a Black Ghost (Nakano being one, though shown to temporarily do so in the OVA) and those who can are usually only able to do so once per day. There is also no known method of how an Ajin can properly materialize a Black Ghost although most of the characters in the series managed to manifest their Ghosts.
- Kei Nagai
- Kōji Tanaka
- Izumi Shimomura
- Shinya Nakamura
- Kō Nakano
- Takeshi Kotobuki
- Masumi Okuyama
- Reiji Akiyama
- Jun Suzuki
- Carley Myers (anime only)
- Kimura (anime only)
- Himeko Tachibana
- It is interesting to note that the anime has opted to give most Ajin red or reddish-brown eyes (such as Kei, Izumi, Kou and Shinya).
- Although there are 47 recorded Ajin in the world, it is speculated that the number is in actuality much higher as most Ajin are not discovered before they die or are in hiding from the government.
- An Ajin uses the largest piece of flesh as a base and collects the smaller pieces for regeneration. However, pieces that are too far away are not collected, but replaced instead.
- An Ajin's body will always return to their original state, no matter the situation. If an obstacle is in the way (for an example a wall) the obstacle is broken apart.
- Chapter 1, Page 9
- Ajin anime, Episode 6
- Chapter 5, Page 2
- Ajin anime, Episode 1
- Chapter 4, Page 14-15
- Chapter 5, Page 2
- Chapter 42, Page 8