Definitions for "Gantz"
Gantz (ガンツ, Gantsu) is a manga and anime series created by Hiroya Oku (奥 浩哉). Gantz tells the story about a teenager named Kei Kurono who dies in a train accident and becomes part of a semi-posthumous "game" in which he and several other people who have recently died are forced to hunt down and kill aliens - the missions in which they take place are often dangerous, and very few members of the team survive (only to be replaced by others who have recently died). The Gantz anime ran for 13 episodes and had a direct sequel called Gantz Second Stage, which continued the series for another 13 episodes.