Somewhere in Tokyo, there is a room. In that room is a black sphere. Periodically, people who should otherwise have died are transferred to the room. There, the sphere gives them special suits and weapons, and sends them out on a mission to kill aliens here on Earth. While these missions take place, the rest of the world is largely oblivious to them. These missions are lethal - few participants survive them. The sphere calls the shots, and it\'s not the slightest bit nice. Its name... Gantz.
The \"Academy Island Incident\" in which four \"kings\" cross paths... Since then, Silver Clansmen Kuroh Yatogami and Neko have been searching for their master, Shiro. Without finding any clues to Shiro\'s whereabouts, the two became disheartened. However, one day, they see HOMRA members Rikio Kamamoto and Anna Kushina being chased by someone.