Character Relationship Map: S.I.U.

Characters

• Kim Seong-beom (played by Uhm Tae-woong) — protagonist

  A foul-mouthed, hot-tempered detective in the violent crimes section, Seong-beom is known for uncanny animal instincts and for never having failed to solve a case. While undercover, he learns that a c...

• Kim Ho-ryong (played by Joo Won) — supporting

  A profiler and former FBI agent, Ho-ryong is assigned as detective Kim Seong-beom's partner in the newly formed Special Investigations Unit. He works with Seong-beom on the murder investigation as the...

• Park Gyung-sik (played by Kim Jung-tae) — supporting

  A figure whose reported death is used to support the official closure of the case: police claim that he and a captain killed each other in a gunfight and fell. Kim Seong-beom questions how the meeting...

• Park In-mu (played by Sung Dong-il) — supporting

  A suspect in the murders of a fellow officer and four other people. Testimony connects him to a gangster boss who allegedly paid him to stay quiet about an earlier arrest. The police authorize Kim Seo...

• Jung Young-soon (played by Lee Tae-im) — supporting

  She contacts Kim Seong-beom after the apparent closure of the investigation, saying she has something to show him. She asks him to meet at the place where Jae-wi was killed, creating a new lead and dr...

• Geun-su (played by Lee Hee-jun) — supporting

  He is among the people who ambush Kim Seong-beom while Kim follows a lead about Kim Jin-hwan. During the confrontation, Geun-su and the others imply that the official account of Seong-beom's son's dea...

• In-mu's Mother (played by Yoo Chang-sook) — minor

  After Kim Seong-beom's son In-mu is killed, his mother is left devastated. She urges Seong-beom to give up police work, becoming a personal voice of grief and concern as he continues pursuing the dang...

Canonical Relationships

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

• In-mu's Mother → Park In-mu (mother)
• Kim Seong-beom → In-mu's Mother (Family Bereaved Parents) — They are united by the death of Seong-beom's son, and his bereaved mother urges him to leave the police.

  After Seong-beom's son, In-mu, is killed, In-mu's Mother is devastated and urges Seong-beom to give up police work.

• Kim Seong-beom → Kim Ho-ryong (Professional Investigative Partners) — Ho-ryong works alongside Seong-beom as they investigate the drug order and the widening police-related case.

  Kim Seong-beom joins the Special Investigation Team, where he works with Kim Ho-ryong on the inquiry.

Story Dynamics

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

• Kim Seong-beom → Park Gyung-sik (Conflict Suspicious Case Participants) — Seong-beom questions the circumstances surrounding the reported gunfight and rejects the apparent closure as suspicious.

  The case is officially closed after Park Gyung-sik and a captain are reported to have killed each other in a gunfight. Seong-beom argues that someone...

• Kim Seong-beom → Jung Young-soon (Narrative Truth-Seeking Contacts) — Young-soon offers Seong-beom information that may renew his search for the truth.

  Seong-beom later meets Jung Young-soon, who says she has something to show him and asks him to meet at the place where Jae-wi was killed.

• Kim Seong-beom → Geun-su (Conflict Ambusher And Target) — Geun-su takes part in an ambush that places Seong-beom in immediate danger.

  While following a lead, Seong-beom is ambushed by Geun-su and others, who imply that he has been brought there to be killed.

Story Analysis

A drug investigation becomes a dangerous inquiry into suspicious police events, forcing Seong-beom to continue seeking answers after the case is officially closed.

Plot Progression

1. A Case Takes Shape — Seong-beom becomes involved in an inquiry into missing methamphetamine and an old gang arrest. He joins the Special Investigation Team and works with Ho-ryong.
2. Clues Beneath the Drug Trail — The investigators question Thai gang members about a large drug order and a repeat buyer. Payphone evidence points to a suspect who is pretending not to understand Korean.
3. A Case Sealed by Gunfire — Disappearances and killings intensify, and Park In-mu becomes a murder suspect. Testimony points to payments connected to an earlier arrest, but the reported gunfight is used to close the inquiry.
4. Loss and Renewed Suspicion — Seong-beom challenges the official account and is punished as the team is disbanded. His son's death and a later ambush deepen his doubts, while Young-soon offers a reason to pursue the truth again.