"Seoha!"
After class ended, Seoha was noisily packing his bag, fully ready to head home, when he turned at the sound of his name. Then he ran over with a bright smile.
"Yes, teacher!"
Why is it that kids that age never just walk normally?
His overflowing energy was both enviable and a little overwhelming.
Looking at him like this, he was clearly just an ordinary elementary schooler…
There was no trace on Seoha's face of the dark aura typical of abused children. Nor did he show the smugness often seen in students who had already finished advanced coursework. Even during addition and subtraction lessons, he participated actively like any other child, and he diligently completed dictation exercises.
Of course, this was thanks to Miyoung and Cheolho repeatedly reminding him that he had to listen carefully to his teacher during class—but Yunmi had no way of knowing that.
"Did you bring another difficult book in your bag today?"
At Yunmi's question, Seoha widened his eyes and nodded.
"Yes. I was going to read it during recess. The kids say it's too hot lately, so they don't play soccer…"
He fidgeted with his clasped hands and glanced toward the door, clearly eager to go home.
"Do you have somewhere you need to rush off to?"
Perhaps embarrassed at having his thoughts exposed, Seoha's face flushed red.
"Ah… no, not really. It's just that Seoeun is waiting for me. She's my little sister, and she's really cute. And Mom only starts cleaning and getting dinner ready once I get home."
Thinking of the baby she'd seen nestled in her mother's arms, Yunmi almost laughed. She really had been adorable.
Ah… what on earth was I thinking?
The tension drained out of her.
Seoha was just a simple, kind-hearted country elementary schooler. Yunmi decided to free this commendable child as quickly as possible.
"Then how about you try solving just these problems? There aren't many—if you finish them all, you can go home right away!"
"Really?"
Seoha asked brightly, as if he'd expected it to take a long time.
"Of course! If there's something too hard, you can just leave it."
He was definitely a smart child.
It was rare, but even among Yunmi's science high school classmates, there had been someone who self-studied middle and high school math from the lower grades of elementary school. That guy was now pursuing a PhD at UCLA.
Seoha probably wasn't on that level—but if he could even solve the middle school curriculum perfectly, Yunmi began to wonder what kind of help would be appropriate.
Before she knew it, Seoha pulled a character pencil with a little duck figurine from his pencil case and began writing his answers.
Problem 1, first-year middle school level.
Ratio and proportion reasoning.
[If 5 cm on a map represents 2 km in reality, how many kilometers would 8 cm represent?]
Scratch, scratch.
[3.2 km]
Seoha wrote the answer almost instantly.
Did he do that in his head at a glance?
Yunmi's eyes twitched slightly as she studied Seoha's face more closely.
His blinking slowed, his breathing became shallow. His lips were half-closed, lightly pressed inward, as he stared at the test paper.
It was clear.
Eager to get home as soon as possible, Seoha had entered a state of complete concentration.
Scratch, scratch.
Problem 2 was the Pythagorean theorem.
[When a right triangle with a base of 8 cm and a height of 6 cm shares one side with a square whose side length is 8 cm, find the distance from a vertex of the square to point O, the midpoint of the hypotenuse of the right triangle.]
After looking at the problem for about two seconds, Seoha's hand began moving immediately.
No way. This one too?
Gulp.
Yunmi swallowed her dry saliva.
This was a problem designed to test reasoning rather than calculation, with a neatly defined answer. Seoha wrote it down as if there were nothing to think about.
[5 cm]
Problem 3, a quadratic equation.
[For a real number m, consider the following quadratic equation:
x² + 2mx + (2m − 1) = 0.
Find all real numbers m such that the equation has two distinct real roots and the difference between the two roots is 2.]
Seoha's pencil moved without hesitation. Yunmi watched, forgetting even to breathe.
In an instant, Seoha recalled the condition involving the discriminant and transformed it into an equation that fit the problem.
There was no pause. No sign of doubt. It meant he was completely certain of the answer.
[m = 0 or m = 2]
Yunmi unconsciously covered her mouth with her hand, afraid a sound might escape.
Simply plugging numbers into the quadratic formula wasn't difficult. But the ability to understand the structure of the problem, modify conditions, and connect them through reasoning was something very special.
Yunmi's heart began to pound violently.
Speed didn't matter. This kind of structural thinking wasn't something that could be taught.
Problem 4: an application of trigonometric ratios.
The calculations were easy, but the problem required a shift in perspective.
Seoha didn't simply substitute values or rely on formulas.
Eight years old—an age where merely grappling with basic arithmetic would already be impressive—yet structural thinking was second nature to him.
And as if it were the most natural thing in the world, he wrote down the correct answer.
Problem 5: differentiation.
[Find the real number a such that the difference between the two roots of
f(x) = x² + 2ax + (2a − 1)
is 2.]
The calculations were brief, and the judgment even faster. Yunmi felt as though she were going crazy with curiosity about what was actually happening inside this child's head.
Holding his pencil, Seoha glanced over the problem once—then immediately began calculating.
An eight-year-old, without hesitating even once, grasped the entire flow in an instant: derivative, location of extrema, and difference between roots.
He read the problem and immediately connected the conditions and the function in his mind. In the process, he didn't go through a single unnecessary step.
That meant Seoha already possessed perfect logic and intuition.
An indescribable emotion brushed through Yunmi's mind.
Was this how it would feel if an elementary school child drew a precise architectural blueprint with crayons? The cold, razor-sharp logic contained within that innocent handwriting felt chillingly out of place.
"I'm done, teacher!"
Had three minutes even passed?
Seoha held out the test paper, his entire body radiating his desire to go home—it was adorable.
"Alright. You got them all right. You can go home."
She was so shocked that her voice came out dry. Realizing it too late, she worried—but Seoha didn't seem to mind at all.
"Yes! Thank you!"
Seoha bowed deeply at the waist, then dashed out in a hurry.
After doing something completely unbelievable, he didn't show even the slightest sign of expecting praise, as if it were nothing special.
Yunmi stood there blankly, watching Seoha run off on his short legs.
She sank into thought.
"What am I supposed to do with you?"
Yunmi stared at the paper in her hands for a long time.
It was something she had never imagined could be possible, even in her dreams. The gap between reality and common sense was so vast that her mind felt completely numb.
She carefully placed the answer sheet into a file so it wouldn't crease, handling it gently—as if protecting a precious treasure from harm.
Tap, tap, tap.
Yunmi drummed her index finger against the desk.
Still only a first grader.
Needless to say, an age that required adult protection. Even if he showed extraordinary talent now, there was always the possibility that he might lose interest in mathematics someday. Yunmi had seen countless gifted children fade away like that.
"If he were just an ordinary prodigy, that is…"
Seoha was something beyond what the word genius could even describe—an anomaly outside all norms.
A shiver ran through her entire body.
Perhaps she was standing in a position where she could influence someone destined to leave their name in history.
Hiss—
She drew in a deep breath, grounding herself in reality.
Her fingertips resting on the desk trembled slightly.
For a long while, Yunmi considered every option available to her. Yet none of them felt right. Why was that? The answer was obvious. She herself had never been a genius. She lacked the foundation needed to judge what path would truly be best.
"I've decided."
When it came to a genius, she would ask another genius—or at least someone close to one.
The burden was far too heavy to carry alone.
Riiing—riiiing—riiiing.
The ringing went on for a long time.
—Wonil? What's gotten into you, calling me of all people?
Only as the ringtone was about to end did an irritated voice come through.
"I have something I want to ask."
There was silence for a long moment. Then, with a resigned sigh, he finally replied.
—Just a moment….
Thump—
Woohyun hurriedly turned off the recording camera.
The blackboard was filled with various graphs and formulas. Why would an ex-girlfriend he hadn't heard from in years be calling now?
At the mention that she had something to ask, Woohyun trudged out of the studio, grabbed a canned coffee from the refrigerator, and popped it open.
Click—
"What is it?"
—There's an incredible genius among the students I teach.
Woohyun let out a snort.
"A genius, my ass. You finally call after years just to say that?"
He was sick of hearing it.
That was the kind of praise that had poured in endlessly when he took second place at the International Mathematical Olympiad, a competition involving over a hundred countries. It had been the second-best result ever achieved by a Korean contestant since the country's first participation in 1988.
But it had all been meaningless. Titles like genius were reserved for the tiny handful truly chosen by God.
—I know what you're thinking, but this is different. I mean, this kid—
But Yunmi didn't get to finish.
"Enough. If that's all you've got, I'm hanging up."
Was he angry?
An air of suffocating silence flowed through the receiver.
Regret washed over him.
Damn it. Should I have handled that better? Why did I have to poke at her like that? I know she hates it when I talk like that.
While Woohyun was hesitating, unsure of what to do…
—You stingy jerk….
"What?"
A vein throbbed at his temple.
—Hey, you stingy bastard!
"You really want to die?"
—How long are you going to stay sulking?
The more he listened, the hotter his temper flared. Everyone had a reverse scale that shouldn't be touched—and she was stomping all over his.
"What do you mean sulking? Is there even one person from our graduating class who earns more than I do?"
Last year alone, he'd paid over five billion won in taxes.
The number-one star instructor worshipped by parents and students alike. The god of mathematics with the best academic pedigree and résumé—Shin Woohyun—and she dared!
But the words that followed instantly cooled his chest.
—If you're so proud of it, why don't you ever come to class reunions?
"…That's because of you. You think it's comfortable for me to see my ex?"
—Don't be ridiculous.
"Enough. I'll listen, so just say it again. What exactly is so special about this kid?"
From the other end came the sound of a relieved exhale.
"An elementary school first grader who perfectly understands and solves calculus, geometry, and vectors."
The moment he heard that, Woohyun frowned.
"Are you still in Gangnam? That kid's parents must be something else. Just how hard did they push him—"
There are a few children like that every year.
When good DNA combines with inhumane early education, kids like that appear with surprising frequency. Most of them quickly get a sense of their place and end up going to medical school.
If they still can't let go of their illusions, they'll appear on programs like Gifted Discovery, show their faces on TV. A joke, really. As if that earns anyone's recognition.
—No. I'm back in my hometown now.
"Ongcheon?"
Back when they were dating, Woohyun had once gone down to her hometown with her.
—Yeah.
"In that backwater village, there's a kid who can solve that stuff?"
—I couldn't believe it either. I called the kid's mom in and talked to her—turns out she's never sent him to an academy, never even taught him at home. The kid figured it all out on his own.
"You're sure she's not lying?"
—Do you think I'd fall for that? I checked multiple times. Oppa, tell me—what am I supposed to do with him? Should I contact a gifted education center? Look into early graduation? I even thought about calling teachers at science high schools, but—
Woohyun cut Yunmi off mid-sentence.
"Don't. You'll ruin the kid. You'll just fill the parents' heads with useless fantasies. And the student will start thinking he's something special and turn arrogant."
—Then what am I supposed to do? I've seriously never seen a kid like this in my life.
"That's just how it is in this country. Abroad, you occasionally see them. Freaks."
Perhaps recalling unpleasant memories, Woohyun's face twisted harshly.
—So you're saying I should just leave him alone?
"Of course not. Assuming what you're saying is true—do you know what kids like that, real geniuses, actually need?"
—Oh, sure. Like I'd know—I'm not a genius.
Even at her sarcastic tone, Woohyun didn't seem bothered in the slightest.
"Overwhelming achievements."
—What?
Caught off guard by the unexpected answer, Yunmi found herself at a loss for words.