Once a dedicated police detective named Yokoda, 8 Man—later known as Hachirō Azuma—was reborn after criminals took his life. Rescued by Professor Tani, Yokoda’s consciousness became the eighth successful transfer into a synthetic body following seven failed trials, thus dubbing him "8 Man." Endowed with superhuman speed, strength, and resilience, along with shapeshifting abilities, he assumed the identity of Hachirō Azuma to mask his android nature from those closest to him, including colleagues, friends, and lover Sachiko. Sustained by specialized "energy cigarettes" carried in his belt, he countered the energy constraints of his cybernetic form. Balancing crime-fighting with secrecy, only Tani and Chief Tanaka knew his true self as he navigated this double life.

The 1993 OVA *8 Man After* depicted a grimmer fate: Azuma vanished after years of service, his demise hinted to stem from an irreconcilable rift between his human psyche and mechanical shell. His body was claimed by Hazama Itsuru, a slain detective whose violent methods defined the new 8 Man. The 1992 film *8 Man: For All the Lonely Nights* reimagined his origin while preserving core elements, spotlighting his battle with identity and isolation—themes echoing through all versions. *8 Man Infinity* diverged with a fresh continuity centered on a successor, shifting focus from Azuma’s legacy.

Across all incarnations, 8 Man relentlessly fought crime—from syndicates to rogue cyborgs—cementing his legacy as Japan’s pioneering cyborg hero. Yet his narratives frequently underscored the psychological burden of his dual existence, especially in stories chronicling his disappearance or succession.