Gantz: G

"Gantz: G" is a manga series that serves as a spinoff of the original "Gantz" series created by Hiroya Oku. While the original "Gantz" follows a group of people who are resurrected after dying and forced to participate in deadly missions against aliens using technology provided by a mysterious black sphere known as Gantz, "Gantz: G" introduces new characters and settings while maintaining some of the core themes of action, survival, and moral dilemmas.