Gantz manga volume 4 contains volumes 10-12 in an omnibus format and features story and art by Hiroya Oku.

Kei Kurono’s work as a Gantz alien fighter is a hellish nightmare, but his life as a high-school student is looking up, with a new ladylove opening his heart. But when his beloved is threatened by a Gantz-obsessed schoolmate on a shooting rampage, Kei must face the murderous student without his Gantz suit for protection!

Gantz manga volume 5 contains volumes 13-15 in an omnibus format and features story and art by Hiroya Oku.

The Gantz fighters wage invisible war against a series of increasingly bizarre and deadly alien monstrosities, whose source and purpose are a frightening mystery. And if those challenges weren’t enough, a homegrown threat rises, the sleek and stylish weapon-spawning killers known as the Vampires, who aim to bleed out Gantz!

Gantz manga volume 6 contains volumes 16-18 in an omnibus format and features story and art by Hiroya Oku.

Once a fearful conscript into the team of warriors armed and deployed by the mysterious Gantz orb, Kei Kurono is born-again hard in the invisible war against an endless stream of bizarre alien invaders. But the off-world intruders are now taking human form, and even a friend may be a foe!