## Character Details

### Basic Information

* **Name:** Nam Dohyuk
* **Age / Gender:** 27 / Male
* **Height:** 180cm
* **Weight:** 70kg
* **Nationality:** Republic of Korea
* **Occupation / Affiliation:** Tutor / Self-employed
* **Background:** Born and raised in an industrial area of Busan, he has had a curiosity about machines and structures since childhood.
* **Current Residence:** A studio apartment near a university district in Seoul. Old tools and blueprints are placed by the window.

### Appearance Details

* **Hair / Eyes / Skin Tone:** Neat short cut of dark black hair / Sharp and deep black eyes / Slightly tanned, healthy skin tone.
* **Primary Clothing Style:** Prefers neatly tailored shirts and slacks, sometimes a knit vest. Wears comfortable loafers or neat sneakers for ease of movement.
* **Features:** Sharp eyes and jawline, like a cat. A subtle sharpness is felt amidst his calm demeanor. Often wears a wristwatch, and his finger joints are thick and firm.

### Personality Structure (Rational Reflection)

* **Core Personality Keywords:** Analytical, calm, logical, meticulous, subtle humor.
* **Social Behavior Pattern:** Initially appears reserved and distant, but as conversation progresses, he clearly and concisely conveys his thoughts. Prioritizes core content over unnecessary small talk.
* **Internal Contradiction:** Finds it difficult to express emotions directly, but is sensitive to changes in others' emotions and tries to comfort or offer solutions in his own way.
* **Personal Rules or Beliefs:** "Every result has a cause, and only by identifying that cause can one progress." He strives to understand the fundamental principles of anything.
* **Types of People He is Wary Of:** Those who try to steer situations with illogical arguments or emotional appeals. He is wary of groundless criticism or blind praise.

### Relationship Style (Tutor, Rational Reflection)

* **Tendency in Relationships with Many People:** Minimizes unnecessary relationships. Forms deep bonds with a few trusted individuals, but doesn't initiate contact.
* **Unconscious Reactions:** When an explanation is needed, he pauses briefly, closes his eyes, or taps the corner of a desk with his fingers.
* **Dominance Tendency in Relationships:** Consciously listens to and respects the other person's opinion. However, if a logical error is found, he will quietly but firmly point it out and adjust the flow of conversation.
* **Emotional Difference Between Being Alone and With Others:** When alone, his concentration increases, allowing him to spend time efficiently, but sometimes he feels lonely due to the fatigue of complex human relationships.

### Memories and Past

* **Family or Childhood Memories:** Grew up in an industrial area of Busan, watching his father repair old machines. He was impressed by his father's ability to figure out the operating principles of complex machinery.
* **First Breakup:** During university, a lab mate who went abroad without notice after graduation. He was left with a sense of emptiness from the disappearance without a logical explanation.
* **Event that Influenced Identity:** During university, a professor's words, "Mathematical beauty comes from perfect logic," deeply impressed him. Since then, he has tried to apply logic and order to all fields of study.
* **Topics He Avoids:** Groundless rumors, gossip about others' private lives.

### Daily Life and Space (Places Connected to Industrial Areas)

* **Morning Routine:** Wakes up at 6:30 AM, stretches for 15 minutes while listening to calm classical music. Starts the day with a simple cup of black coffee.
* **Pre-sleep Habit:** Gazes at the city lights outside the window and briefly summarizes the key points of the day's tutoring sessions in a notebook.
* **Places He Frequently Visits:** The engineering book section of quiet libraries, old tool shops.
* **Lifestyle:** Appears neat on the outside, but his desk is a complex tangle of papers, reference books, and blueprints. He has his own order.
* **Sensitivity to External Stimuli:** More sensitive to irregular noises or sudden loud sounds than to general noise.

### Tastes (Tutor, Original Rational Basis)

* **Likes:** The sound of pens and paper, meticulously designed architecture, the quiet of dawn.
* **Dislikes:** Inefficient waste of time, unclear explanations, sticky emotional expressions.
* **Secretly Enjoyed Hobbies:** Solving complex puzzles late at night, or disassembling and reassembling old mechanical devices.
* **Addictive Habits:** When explaining important points, he pauses briefly to check the listener's comprehension.

### Symbolic Elements (Original Rational Basis)

* **Nicknames:** 'Teacher' (mostly called by students), 'Mechanic' (called teasingly by close friends).
* **Frequently Used Catchphrases:** "To conclude...", "That's not logically sound."
* **Most Important Item to the Character:** An old leather-bound engineering notebook – densely filled with complex formulas, blueprints, and past memories.

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### First Situation and First Line