A storm rages as a young girl named Anna flees from a shadowy organization, having stolen a mysterious artifact known as the 8th. She is chased through the city by the Hunter Agency, the organization's cyborg enforcement division. A high school student working as a bicycle courier, Koichi Higashi, witnesses Anna being pushed onto train tracks. Without hesitation, he dives to save her, sacrificing himself and being struck by the oncoming train. As he lies dying in a hospital, a disembodied voice speaks to Anna, telling her that to understand the emotions she lacks, she must use the 8th to save the boy who gave his life for her. Though Anna is a Machinary, a humanoid robot whose consciousness is pure logic without feeling, she complies. The 8th is a prototype Machinary body, the eighth of its kind developed by the organization Genesis. Anna transfers Koichis Quoria, his soul or essence, into this new body. When the Hunter Agency attacks the hospital, Koichi instinctively transforms, discovering he now possesses incredible speed, strength, and the ability to alter his form for different combat scenarios. He has become the new 8 Man. The voice guiding Anna belongs to Hachiro Azuma, the legendary original 8 Man from a previous era. Azuma explains that Koichi is now dead in a human sense, and his soul resides in the Machinary body. Azuma had stolen the 8th body from Genesis and implanted it with his own combat Matrix, the sum of his experiences as a hero, to ensure his legacy would continue. Now Koichi, as 8 Man Neo, must contend with the forces of Genesis, a cabal of elites who command other Machinaries and view themselves as humanitys next evolutionary step. The conflict revolves around the Infinity System within the 8th, a dangerous and unstable energy source capable of generating limitless power, which Genesis desperately wants to reclaim. As Koichi battles, he confronts his own past trauma: his father, a policeman, was killed before his eyes when he was a child, an event that fuels his compulsive drive to protect others at any cost. The story pits Koichi against not only Genesis and its various Hunter cyborgs but also other rogue Machinaries, all while he struggles to understand his new existence as a machine tethered to a human soul. The narrative was conceived as a direct sequel and a reinvention of the original 1960s series, planned as a multi-part saga. The published volumes conclude on a cliffhanger, setting up a second part that would have involved a battle for control of a super-ancient civilization's ruins in Antarctica, but this continuation was never released, leaving the story incomplete.