Gantz (Japanese: ガンツ, Hepburn: Gantsu) is a Japanese manga series written and illustrated by Hiroya Oku. Gantz tells the story of Kei Kurono and Masaru Kato, both of whom died in a train accident and become part of a semi-posthumous "game" in which they and several other recently deceased people are forced to hunt down and kill aliens armed with a handful of futuristic items, equipment, and weaponry. Both the manga and anime are noted for their heavy violence and sexual content. The Gantz anime adaptation, directed by Ichiro Itano and animated by Gonzo, contains 26 episodes divided into two seasons. A series of two live action movies based on the manga were produced and released in January and April 2011. A CGI anime film, Gantz: O, was released in 2016.