The city of Sternbild is home to many people of different races, backgrounds, and those who are called Next. Next are people who possess special powers. They are the superheroes who protect peace within the city. The story mainly focuses on veteran hero Kotetsu T. Kaburagi aka Wild Tiger who is assigned with a new partner, a young man named Barnaby Brooks Jr. However, Barnaby and Kotetsu usually have trouble working together as they have conflicting opinions on how a superhero should act while at the same time trying to crack the mystery of the murder of Barnaby's parents. In addition, the appearance of a homicidal vigilante NEXT named "Lunatic" stirs up the public and makes them question the meaning of heroes.