During the Emerald City Comic-Con panel earlier this month, it was announced that Dark Horse Comics plans to release the Hiroya Oku and Keita Iizuka’s Gantz G three-volume spinoff manga. The first volume of the spinoff manga is to arrive on June 13.
Dark Horse describes the story:
Victims of a lethal bus plunge wake in a schoolroom where an ominous black sphere announces Your lives have ended. How you use your new lives is entirely up to me. Thus, a new Gantz team is sent to fight bizarre aliens that will show how the dead can die!
Gantz: G, or also previously provisionally titled G-Gantz, is a spin-off manga to Gantz. It was first announced in the November 2015 issue of Miracle Jump, written by Hiroya Oku and drawn by mangaka Iizuka Keita. The manga was launched in the December issue on November 17th, 2015 and finished on March 17th, 2017.
Oku launched the original Gantz manga in Young Jump in 2000, and he ended the manga in 2013. Shueisha published the 37th and final volume in Japan in August 2013.