Character Relationship Map: Good Boy

Characters

• Yun Dong-ju (played by Park Bo-gum) — protagonist
• Ji Han-na (played by Kim So-hyun) — protagonist
• Min Joo-young (played by Oh Jung-se) — supporting
• Kim Jong-hyeon (played by Lee Sang-yi) — supporting
• Ko Man-sik (played by Heo Sung-tae) — supporting

Canonical Relationships

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

• Yun Dong-ju → Ji Han-na (Lovers) — Professional partners evolve into romantic allies through shared danger and mutual trust.

  "Han-na uses a surprise kiss as an investigation excuse in Ep6; the pair conducts joint fieldwork and executes a high-stakes rescue mission in Ep9, so...

• Yun Dong-ju → Ko Man-sik (Commander & Operative) — Superior officer who recruits and protects Dong-ju, navigating internal unit politics.

  "Man-sik suggests forming the special team and later fights to keep it together after Dong-ju's assault triggers a major crisis in Ep7."

• Kim Jong-hyeon → Ko Man-sik (Recruiter & Investigator) — Man-sik directs Jong-hyeon's prosecutorial expertise toward the team's core investigation.

  "Man-sik requests Jong-hyeon to head to the Prosecutors' Office to investigate Gyeong-il's case, formally integrating him into the special unit."

Story Dynamics

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

• Yun Dong-ju → Min Joo-young (Revenge & Counterstrike) — Post-disbandment rivalry escalates into a personal vendetta with lethal consequences.

  "After the team disbands, Dong-ju quietly prepares solo revenge against Joo-young; Joo-young catches on and launches a counterstrike, leading to Dong-...

• Ji Han-na → Min Joo-young (Target & Perpetrator) — Han-na's personal investigation into her father's past directly intersects with Joo-young's criminal network.

  "Han-na receives her father's case files linked to Joo-young's operations; Joo-young's gang later kidnaps Han-na, forcing a direct rescue operation."

• Yun Dong-ju → Kim Jong-hyeon (Teammates) — Dependent field partners who coordinate investigations and execute joint tactical operations.

  "Both join the Special Criminal Investigation Team; they coordinate evidence gathering and jointly rush to rescue Han-na in Ep9, demonstrating reliabl...

• Kim Jong-hyeon → Min Joo-young (Investigator & Suspect) — Jong-hyeon's prosecutorial investigation targets Joo-young's criminal infrastructure.

  "Jong-hyeon investigates Joo-young's drug smuggling and burner phone connections; Joo-young's operations directly threaten Jong-hyeon's prosecutorial...

• Ji Han-na → Kim Jong-hyeon (Teammates) — Fellow unit members who share investigative duties and tactical response responsibilities.

  "Both operate as members of the Special Criminal Investigation Team; they coordinate field operations and participate in the emergency rescue mission...

Story Analysis

Overall narrative architecture across 1 season tracking a demoted officer's journey through team formation, criminal investigation, and ultimate redemption.

Plot Progression

1. Season 1: Demotion & Formation — Dong-ju is demoted to Inseong and joins a newly formed special team of former medalists, setting the stage for a high-stakes investigation into Ju-yeong.
2. Season 1: Investigation & Complications — The team uncovers Ju-yeong's burner phone and drug network, faces prosecution intervention, and navigates internal crises while Han-na retrieves her father's case files.
3. Season 1: Crisis & Kidnapping — Dong-ju's assault triggers team disbandment, customs infiltration leads to a trap, and Han-na's kidnapping forces a desperate rescue mission amid escalating danger.
4. Season 1: Disbandment & Solo Revenge — Post-disbandment, Dong-ju plans a solo revenge against Ju-yeong, triggering a counterstrike and countdown challenge that pushes both sides to desperate measures.
5. Season 1: Final Showdown & Resolution — The team reunites for a final all-out attack, faces a devastating city-wide counterattack, and culminates in a decisive battle that determines the city's fate.