Dr. Brain — Characters & Cast

To uncover the truth behind his son's supposed death and his wife's coma, evolving into a desperate mission of familial rescue and moral atonement.

Begins as an emotionally detached neuroscientist incapable of empathy due to an atypical brain morphology. Following his family's tragedy and through repeated brain syncs, he assimilates emotional residue from others, transforming from a cold logician into a deeply protective father and grieving husband who risks his sanity to rescue his son.

To protect her son Doyoon at any cost and validate the maternal conviction that he is still alive.

Initially depicted through memories and hospital visits as a wife driven to despair by Sewon's emotional coldness and their son's disappearance. When Sewon accesses her comatose mind, her fierce maternal instinct and hidden knowledge become the emotional compass guiding him to the truth.

To uncover the truth behind his own murder and protect Sewon from the killers.

Introduced as a gritty, pragmatic private investigator collaborating with Sewon to solve a connected murder. In a central psychological turn, it is revealed that Kangmu was murdered prior to their partnership, and the version operating beside Sewon is a living neural manifestation within Sewon's own synced mind.

To uphold justice, solve high-profile homicides, and prevent the conspiracy from silencing key witnesses.

Initially views Sewon as an prime suspect in strange deaths and disappearances. As forensic inconsistencies mount and Sewon provides impossibly accurate crime scene details, she suspends disbelief and becomes his critical ally in exposing institutional corruption.

To cheat death and achieve physical and intellectual immortality via neural transfer.

Appears early on as Sewon's benevolent childhood mentor and scientific benefactor. He is later unmasked as the mastermind seeking digital and biological immortality by harvesting compatible young savant brains to host his own consciousness.