Character Relationship Map: Misbehavior

Characters

• Park Hyo-joo (played by Kim Ha-neul) — protagonist

  Park Hyo-joo is a part-time chemistry teacher who becomes a homeroom teacher after a colleague takes maternity leave. Envious of Hae-young's privileged appointment, she discovers Hae-young's affair wi...

• Hae-young (played by Yoo In-young) — supporting

  Hae-young is a newcomer who gains a tenured teaching position through her rich connections. She has a sexual relationship with Jae-ha and becomes the target of Park Hyo-joo's threats. Her connection w...

• Jae-ha (played by Lee Won-keun) — supporting

  Jae-ha is a student involved in a relationship with Hae-young and later an affair with Park Hyo-joo. Park enrolls him in ballet classes, and he wins second place in a competition. He maliciously revea...

• Jae-ha's father (played by Ki Joo-bong) — supporting
• Chairman (played by Lee Kyung-young) — supporting

  Chairman is Hae-young's father and the chairman of the board. His influence is established when Park Hyo-joo asks Hae-young to negotiate with him after Park's teaching contract is not renewed. The plo...

Canonical Relationships

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

• Jae-ha's father → Jae-ha (father)
• Park Hyo-joo → Chairman (Power Institutional Authority) — Park is vulnerable to the institution represented by the Chairman.

  After Park Hyo-joo's contract is not renewed, she begs Hae-young to negotiate with the Chairman, who is identified as the board chairman.

• Hae-young → Chairman (Family Daughter And Father) — The Chairman is Hae-young's father and a powerful family connection.

  The plot identifies the Chairman as Hae-young's father when Park Hyo-joo asks Hae-young to negotiate with him.

• Park Hyo-joo → Jae-ha (Professional Teacher And Student) — Their school-related relationship becomes personally complicated.

  Park Hyo-joo is a high-school teacher and enrolls Jae-ha in ballet classes for his upcoming competition.

• Hae-young → Jae-ha (Romantic Sexual Affair) — Their affair is intense but emotionally insincere from Hae-young's perspective.

  Park Hyo-joo discovers Hae-young having sex with Jae-ha, and Hae-young later says she never truly loved him.

• Park Hyo-joo → Hae-young (Professional Colleague) — They work in the same school but occupy unequal professional positions.

  Park Hyo-joo is a part-time chemistry teacher and becomes jealous of newcomer Hae-young, another teacher at the school.

Story Analysis

A lonely teacher's envy, desire, and manipulation escalate into murder and institutional consequences.

Plot Progression

1. Jealousy Behind the Classroom — Park Hyo-joo takes over homeroom duties while resenting Hae-young's privileged path to tenure. Personal pressure and gaslighting leave Park increasingly isolated.
2. The Affair Exposed — Park discovers Hae-young having sex with Jae-ha and uses the secret as leverage. Her threat changes the balance between the two teachers.
3. Desire and Deception — Park supports Jae-ha's ballet competition and begins an affair with him. His second-place result briefly contrasts with the increasingly deceptive relationship.
4. A Career in Ruins — Jae-ha reveals that the affair was meant to give Hae-young leverage over Park. Park loses her contract and seeks help through Hae-young's family connection.
5. The Hotel's Fatal Reckoning — Hae-young admits that she never loved Jae-ha, provoking Park to kill her with boiling water. Jae-ha then rejects Park, discovers the corpse, and faces the police aftermath.