Kei Kurono (voiced by Daisuke Namikawa) and Masaru Kato (voiced by Masashi Osato) were good friends in elementary school. After a chance encounter one day, the two died at the same time while trying to save a stray dog on the railroad tracks. However, what awaits them is not nothingness. When Kei Kurono opens his eyes, he sees an unheard-of luxury apartment. Around him gather the "dead" who are as confused as him and do not know each other. "Your life is over. How to use your new life is my freedom," a black sphere named "GANTZ" in the center of the room conveys such instructions. In order to survive, they are forced to participate in various brutal battles with alien monsters. After each battle, the "dead" will get corresponding scores according to their performance in the battle. With these scores, the "dead" can choose to realize their wishes or exchange for powerful weapons to participate in the next battle. Those with a score of 0 face terrible punishment. What exactly is "GANTZ"? Who controls this bloody game? Can it really be resurrected? In order to solve all these questions, Kunye Ji has only one choice, and that is to fight to the end.