Kei, a high school student, discovers that he has become immortal. However, this does not make him a superhero in the eyes of the general public and governments. Instead, they view him as an unusual specimen who must be captured and subjected to scientific experiments for the benefit of humanity. Despite his newfound ability to live forever, Kei faces the harsh reality that he will have to die many times over for the sake of others.
The show's lead character is a 17-year-old male ajin who faces opposition from his younger sister, eriko, due to her perception of him as being worthless....
This individual is known as an Ajin, which stands for "demi-human." Despite their outward appearance of being content and composed, they have no qualms about ending the lives of other people....
High-ranking member of the ministry of health, labor, and welfare. He is intent on stopping Satous plan for a new Ajin nation....