Daisuke Ido, a cyberphysician exiled from the floating city of Tiphares, survives a seven-year fall to the Scrapyard below. After struggling to establish himself as a medic, he adopts the dual life of hunter-warrior and apprentice under veteran cyberphysicians Gauss and Dedekind. Mastery of cyborg medicine allows him to open his own clinic, where he revives Alita from discarded remains, crafting her first civilian cyborg body. Their bond deepens into a father-daughter dynamic, marked by his initial resistance to her hunter-warrior ambitions and eventual support for her Motorball career and independence.

Ido secretly pursues combat as a hunter-warrior, wielding a self-designed rocket hammer and relying on ambush tactics honed through raw physical strength. His clandestine violence clashes with his healing persona until a fatal clash with Zapan leads to resurrection by Desty Nova. This rebirth unveils Tiphares’ brain bio-chip conspiracy, pushing Ido toward psychological collapse. To survive, he erases traumatic memories, retaining only medical knowledge, and retreats to Farm 21 with nurse Kayna—whose unrequited affection complicates their partnership.

Compassionate yet haunted by repressed aggression, Ido hides a fear of heights exposed during a hostage crisis. His brief romance with cloned patient Carol and a professional alliance with Chiren (implied in the non-canon OVA to share a past) underscore his fractured connections. After Nova restores his erased memories via pill, Ido resumes cybermedicine but grapples with Tiphares’ ethical rot.

Armed with rocket hammers, repurposed pipes, and later a sledgehammer, he navigates the Scrapyard’s brutality, balancing trauma and resilience. His duality as healer and fighter defies the wasteland’s harshness, even as he questions the cost of survival in a world shaped by floating cities and fallen exiles.