Character Relationship Map: Dr. Brain

Characters

• Koh Se-won (played by Lee Sun-kyun) — protagonist

  He is the central protagonist, a genius brain scientist who remembers everything he sees. After his mother died in a hit-and-run accident during his childhood, he devoted himself to brain research. As...

• Lee Kang-mu (played by Park Hee-soon) — protagonist
• Lieutenant Cho (played by Seo Ji-hye) — supporting
• Jung Jae-yi (played by Lee You-young) — supporting
• Hong Nam-il (played by Lee Jae-won) — supporting
• Secretary Yoon (played by Teo Yoo) — supporting
• Dr. Hahn (played by Cha Hee) — supporting

Canonical Relationships

Family, romantic, and professional connections based on plot evidence.

• Koh Se-won → Jung Jae-yi (Spouses) — Deeply bonded couple navigating profound loss, with Jae-yi's insights catalyzing Se-won's investigation into their son's death.

  "S1E1-E2 establishes their marital bond and shared grief over Doyoon, with Jae-yi's prior suspicions about the accident driving Se-won's neural syncs....

• Koh Se-won → Hong Nam-il (Controller) — Power dynamic where the antagonist exerts psychological and physical control over Se-won's family, forcing a desperate counter-offensive.

  "S1E5-E6 details the mastermind's control over the family's ordeal, culminating in a life-risking confrontation to break the manipulation and save his...

• Koh Se-won → Dr. Hahn (Mentor) — Academic predecessor whose pioneering brain sync technology provides the scientific foundation for Se-won's investigative methods.

  "S1E6 references harnessing unique brain power and synced knowledge, rooted in Dr. Hahn's foundational research on neural synchronization that enables...

• Koh Se-won → Lee Kang-mu (Colleague) — Professional collaborator who provides investigative intel and technical support for Se-won's brain sync operations.

  "S1E2 notes that PI intel drives Se-won to conduct more brain syncs, with Lee Kang-mu assisting in tracking leads and analyzing data across episodes."

• Lee Kang-mu → Secretary Yoon (Mastermind/Subordinate) — Hierarchical control within the antagonistic organization.

  "Episode 3 and 5 summaries show the mastermind directing corporate operations and staff to cover up the conspiracy."

• Jung Jae-yi → Lee Kang-mu (Former Associate/Controller) — Historical entanglement where corporate power influenced personal decisions.

  "Episode 4 and 5 summaries imply Jae-yi's past ties to the conspiracy orchestrated by the mastermind."

• Jung Jae-yi → Secretary Yoon (Workplace Associate) — Professional contact within Jae-yi's social or work circle, providing indirect context about the family's external connections.

  "S1E4 mentions Heejin, daughter of a man connected to Jae-yi, revealing workplace and social ties that impact the home life and investigation."

• Koh Se-won → Secretary Yoon (Scientist/Corporate Staff) — Professional distance highlighting the bureaucratic machinery behind the conspiracy.

  "Episode 3 summary reveals a disturbing truth about the private investigator, implicating corporate staff in the cover-up."

Story Dynamics

Alliances, conflicts, and narrative interactions that evolve throughout the story.

• Koh Se-won → Lieutenant Cho (Adversary) — Law enforcement figure who views Se-won's unauthorized investigations as a threat, leading to professional and personal conflict.

  "S1E3 states Se-won becomes a target during his investigation, drawing law enforcement attention and creating friction as he operates outside official...

Story Analysis

Overall narrative architecture across all 1 seasons

Plot Progression

1. Season 1: The Accident & Syncs — Se-won introduces his neural sync technology after a family tragedy, while his wife's suspicions push him to investigate beyond official reports.
2. Season 1: The Investigation Deepens — External intel drives deeper syncs, but Se-won's methods make him a target, revealing dark secrets about his allies.
3. Season 1: Truths Uncovered — Testimonies and hidden documents expose the family's past connections, shifting the focus from accident to conspiracy.
4. Season 1: The Mastermind Emerges — The antagonist is identified, and Se-won learns the full scope of the diabolical plan targeting his family.
5. Season 1: Climax & Sacrifice — Se-won weaponizes synced memories, confronts the mastermind, and risks his life to secure his family's safety.