On an ordinary evening, college student Kei Kurono (played by Ninomiya Kazuya) reunited with his junior high school friend Kato Masaru (played by Matsuyama Kenichi) at the tram station. In order to rescue a man who fell on the rails, the two of them were hit hard by the tram. However, in the blink of an eye, they came to a closed room unscathed. There are seven other men and a huge black sphere here. According to the instructions of the black ball, this group of people need to put on combat uniforms and take up weapons to assassinate the Onion Star. Some people have invested in the killing game for the bonus, while others are ruthless for survival. At the critical moment of life and death, the cowardly Aji and the kind-hearted Asheng have to participate in it, and there are more tests waiting for them ahead. In addition, what secrets does the system called GANTZ hide? This film is divided into two parts, the front and the back, adapted from the original work of the same name by cartoonist Hiroya Oku.