Character Relationship Map: Hidden Face

Characters

• Sung-jin (played by Song Seung-heon) — protagonist

  Sung-jin is the orchestra's conductor and Su-yeon's fiancé. After she leaves a video message saying she is going to Berlin, he struggles with her disappearance and becomes involved with Mi-ju, the cel...

• Su-yeon (played by Cho Yeo-jeong) — protagonist

  Su-yeon is a cellist in the orchestra and Sung-jin's fiancée. She leaves him a video message about going to Berlin and her doubts about marriage, but is later revealed to be trapped in a hidden room i...

• Mi-ju (played by Park Ji-hyun) — supporting

  Mi-ju is a cellist who auditions for the orchestra as Su-yeon's replacement. She grows intimate with Sung-jin while he is waiting for Su-yeon to return, and the two spend time together at his home. Su...

• Su-yeon's Friend (played by Koh Na-young) — supporting
• Su-yeon's Friend (played by Son Eun-ho) — minor
• Sung-jin's Mother (played by Cha Mi-kyeong) — supporting
• Su-yeon's Friend (played by Joo Ye-rin) — supporting
• Su-yeon's Friend (played by Lee So-young) — supporting

Canonical Relationships

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

• Sung-jin's Mother → Sung-jin (mother)
• Sung-jin → Mi-ju (Romantic Lovers) — Their intimacy develops while Sung-jin is waiting for Su-yeon, then becomes part of the dispute over what happened in the house and who bears responsibility.

  Sung-jin becomes involved with the cellist who auditions to replace Su-yeon, and their relationship grows intimate. He later suspects Mi-ju came to th...

• Sung-jin → Su-yeon (Romantic Fiancés In A Deteriorating Relationship) — Their engagement is unsettled by Su-yeon's disappearance and Sung-jin's involvement with Mi-ju; it ends in a confrontation over whether his inaction amounts to imprisoning Su-yeon.

  Su-yeon's video message says she no longer understands their relationship, doubts her feelings, and does not believe she is ready for marriage. Later,...

Story Dynamics

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

• Su-yeon → Mi-ju (Conflict Rivals In A Hidden Triangle) — Their connection is shaped by Mi-ju's intimacy with Su-yeon’s fiancé and Su-yeon's forced observation of their encounters; the account leaves Mi-ju's intentions uncertain.

  While trapped in the hidden room, Su-yeon secretly watches Sung-jin's encounters with Mi-ju. Sung-jin later confronts the possibility that Mi-ju came...

• Su-yeon's Friend → Su-yeon (friend)
• Su-yeon's Friend → Su-yeon (friend)
• Su-yeon's Friend → Su-yeon (friend)
• Su-yeon's Friend → Su-yeon (friend)

Story Analysis

A disappearance, an affair, and a hidden room converge in a confrontation about cruelty, responsibility, and the difference between abandonment and imprisonment.

Plot Progression

1. A Departure Without Answers — Su-yeon leaves Sung-jin a message saying she is going to Berlin and is unsure about their relationship or marriage. Her absence disrupts the orchestra, while the belongings left behind make her depart...
2. A Replacement Draws Near — Mi-ju auditions for the orchestra and grows intimate with Sung-jin. Their conversation and his concerns about Su-yeon's behavior deepen the uncertainty surrounding her disappearance.
3. Pressure Behind Appearances — Sung-jin feels sidelined by public orchestra decisions, while Su-yeon is criticized as cold and difficult. The story reveals a hidden room in the house, equipped with restraints and a mirror.
4. A Witness Behind the Mirror — Su-yeon is trapped in the hidden room and watches Sung-jin's encounters with Mi-ju. Sung-jin eventually discovers her as she begs to be released.
5. The Meaning of Leaving Her There — Sung-jin confronts the possibility that Mi-ju knew Su-yeon was being watched and admits he allowed Su-yeon to remain trapped after events went wrong. He blames Mi-ju as the confrontation ends without...