The story begins when a pair of high school students (Kei Kurono and Masaru Kato) are seemingly run over by a subway train, after saving the life of a homeless drunk who had fallen onto the tracks. Following their untimely deaths, Kei and Masaru find themselves transported alive and well along with a number of people who have also just died, to the interior of an unfurnished Tokyo condominium from which the Tokyo Tower may be seen and none of them are able to leave. At one end of the room is a featureless black sphere we later learn is called "Gantz". After a short amount of time, a postwar Japanese exercise radio begins to play from the sphere. By way of green text that appears on the surface of the sphere, Gantz informs those present that their lives have ended. The following words appear on the black sphere's surface: "Your lives have ended. What you do with your new lives is entirely up to me.