Kei Kurono college student (Kazunari Ninomiya) see their former childhood friend Masaru Kato (Kenichi Matsuyama) who help a drunken man fell on the subway line. Kei Kurono help them salt in two moments later but watched helplessly subway approaching speed. In the next moment they wake up in a strange room with a giant sphere called “Gantz”. They are assigned some tasks and if the missions are completed in a timeframe they receive points. If they manage to gather 100 points have a chance to return to earth, and if not will perish forever.