Hachirou Oka  

, 岡 八郎

Oka Hachirou is an exceptionally skilled Gantzer from the Osaka Team who has gained a reputation as a legend in his field. He is known for his tactical prowess and hand-to-hand combat skills, utilizing all of his equipment to its fullest potential. His advanced suit is equipped with a variety of features including an X-ray scanner, beam weapon that fires out of the palms, sharp swords protruding from the back of the elbows, complete concealment of the body wearer, and the ability to unhook arms from larger robotic arms for greater flexibility in combat. Oka is also known for his ability to retreat gracefully when faced with an opponent he cannot defeat, without allowing emotions to cloud his judgment. He fights with a variety of weapons including a mecha, flying monowheel, H-gun, and a normal "Gantz sword".