In 2038, an undead virus pandemic causes mutations in human DNA. Infected people show various symptoms and, in fatal cases, turn into highly violent undead. Genius scientist V.E developed Etheru, a virus treatment, but once it becomes undead, it cannot be cured.
However, some people who used Etheru gained superpowers they had never seen before, and the more they used Etheru, the stronger their abilities. People called these developed superhumans Etheruko, which means children of the Etheru.
Among the Etherukos, some try to help humans with their superpowers, but some can't control their power and cause disasters, and some use their superpowers to bring chaos.
Due to the spread of the virus, the undead flocked to the city. New Tokyo was isolated by the district, and the central government was paralyzed. The militia in the district alone was insufficient to defend the undead, and the situation only worsened.
In this situation, the district leaders asked Etherukos to establish an Etheruko office to protect the city from undead and outlaws, solve the city's problems, and rebuild the city.