Character Relationship Map: S Diary

Characters

• Na Jin-hee (played by Kim Seon-a) — protagonist

  Na Jin-hee is the central character, a woman whose boyfriend suddenly ends their relationship after admitting that he wanted intimacy rather than commitment. Troubled by this explanation, she investig...

• Jeong-seok (played by Kim Soo-ro) — supporting

  Jeong-seok is one of Na Jin-hee's three former lovers and is described as her macho college lover. After her latest breakup raises doubts about the sincerity of her past relationships, Na Jin-hee retu...

• Yu In (played by Gong Yoo) — supporting

  Yu In is one of Na Jin-hee's former lovers. He is portrayed as inexperienced and earns a living as a wandering artist. As part of her attempt to understand why her relationships failed, Na Jin-hee rev...

• Jin-hee's mother (played by Na Moon-hee) — supporting
• Gu-Hyeon (played by Lee Hyeon-woo) — supporting

  Gu-Hyeon is one of Na Jin-hee's three former lovers and is characterized by strong religious beliefs. When Na Jin-hee examines her romantic past after being rejected by her current boyfriend, Gu-Hyeon...

• Yu In's Friend 3 (played by Shin Dong-hwan) — supporting

Canonical Relationships

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

• Jin-hee's mother → Na Jin-hee (mother)
• Na Jin-hee → Yu In (Romantic Former Lovers) — Their relationship offers Na Jin-hee a fresh beginning and domestic affection, though the unexpected arrival of Yu In's mother reveals complications in their shared life.

  The plot says Na Jin-hee begins a relationship with Yu In, and that they share a home and affection. It also describes complications when his mother a...

• Na Jin-hee → Jeong-seok (Romantic Former Lovers) — Their affectionate relationship leaves Na Jin-hee with memories and unresolved questions. She later confronts Jeong-seok about their past and what he owes.

  The plot says Na Jin-hee becomes involved with Jeong-seok and recalls their warmth and intimacy. Later, they argue about their relationship and how mu...

• Na Jin-hee → Gu-Hyeon (Romantic Former Lovers) — Their tender first romance ends when Gu-Hyeon leaves. Their later reunion exposes a lasting disagreement about whether religious forgiveness can resolve the pain of their past.

  The plot describes Gu-Hyeon as Na Jin-hee's first love and says he tutored her tenderly before leaving to study abroad. Years later, they reunite; he...

Story Dynamics

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

• Yu In's Friend 3 → Yu In (friend)

Story Analysis

Na Jin-hee's diary follows her attempts to understand past relationships and confront the hurt they left unresolved.

Plot Progression

1. Love Under Pressure — Na Jin-hee seeks reassurance and commitment, while her boyfriend says her demands make him feel trapped. She begins to recognize a painful pattern in her relationships.
2. The First Love's Reckoning — The diary recalls Gu-Hyeon's tenderness, his departure to study abroad, and Na Jin-hee's exam success. Their later reunion as he is a priest brings unresolved pain and a demand for accountability.
3. A Love Remembered — Na Jin-hee recalls warmth and intimacy with Jeong-seok. His written choice of stability over love, the recipe, and memories linked to credit-card bills leave her with questions about their past.
4. A New Domestic Beginning — As the century turns, Na Jin-hee hopes for a fresh start and shares a home with Yu In. His mother's unexpected arrival brings a complication into their domestic life.
5. Settling Old Accounts — Na Jin-hee returns to encounters with men from her past and seeks to settle unresolved hurt. Her argument with Jeong-seok centers on their history and what he owes, while the diary traces her anger an...