Gantz: O (styled as GANTZ:O ) is a 2016 Japanese CGI anime science fiction action film directed by Yasushi Kawamura, produced by Digital Frontier , written by Tsutomu Kuroiwa and based on the manga series Gantz , which was written and illustrated by Hiroya Oku . [2] [3] It was released in Japan by Toho on October 14, 2016.