First appearance: Chapter 268
Oka Hachirou is an almost legendary Gantzer from the Osaka Team, a veteran of numerous games. It's said he has scored at least a hundred points seven times. Oka excels as both a tactician and a hand-to-hand combatant, utilizing his equipment to maximum effect. His advanced suit allows him to remain invisible and hidden until he identifies the strongest alien present. Even though his gear is superior, he knows when to retreat if faced with an unbeatable foe, keeping his emotions in check.
The advanced suit features an integrated X-ray scanner, palm-mounted beam weapons, sharp swords extending from the back of the elbows, and full-body concealment that prevents any psychic attacks from being effective. The wearer can detach their arms from the larger robotic appendages to use additional weapons and equipment.
In addition to his suit, Oka battles with a mecha, a flying monowheel, an H-gun, and a standard "Gantz sword".
