One Saturday morning in December,
Seoha woke up earlier than usual.
Outside the window, the world was bright to a strange degree. The light seeping through the curtains was different from the norm.
“Oh?”
He opened the window to find that the world had turned completely white.
It was the first snow. And quite a lot had fallen.
The persimmon tree in the yard, the flower bed in front of the main gate, and even the roof—everything was covered in snow as though a fluffy cotton blanket had been laid over it.
“Wow!”
A shriek came from the next room, where Seoeun was.
Soon after came the sound of pattering footsteps.
“Oppa! It’s snow! It’s snow!”
Seoeun, still in her pajamas, burst into Seoha’s room.
Her cheeks were flushed a pinkish-red like rouge. With sparkling eyes, she kept letting out exclamations of wonder—she was clearly very excited.
“There was barely any yesterday, but it looks like it came pouring down overnight.”
“Let’s go out and play!”
Seoeun looked up at Seoha with a face full of expectation.
Seoha liked this expression of his younger sister. The face that firmly believed her Oppa would do anything she wanted.
“Let’s go out after breakfast!”
“Really?”
Seoeun jumped up and down, rejoicing.
Miyeong, who had approached them at some point, watched the siblings with a pleased gaze.
“Seoeun, do you like snow that much?”
Miyeong had been worried about having to shovel snow since last night, but seeing her daughter so happy made her heart melt.
“Yeah! I love it so much. Mom, come play with us too!”
“Mom will roast sweet potatoes and wait here. Go with Oppa and come back.”
After breakfast, the siblings dressed snugly in winter clothes.
Seoeun suited up completely in a baby pink padded jacket, a fur hat, and mittens.
“Ready?”
“Yeah!”
When they stepped out into the yard, the cold air brushed against their cheeks. But the snow-covered scenery was so beautiful that the two forgot all about the cold.
“Woooow!”
Seoeun looked around in wonder.
Then she began to waddle and run.
“You look like a penguin.”
Seoeun, puffed up from wearing multiple layers of thick clothing, flapped her arms and rejoiced.
At first, Seoha had only intended to play along with his younger sister, but before he knew it, he was caught up in the fun too, running around with her and building a snowman.
After playing for a good while, both siblings’ clothes were covered in snow.
“Achoo!”
Seoeun sniffled, her nose turning red.
“Let’s go in now.”
Seoha brushed the snow off his sister’s body and then lifted her up lightly.
Seoeun clung tightly to Oppa’s body.
When they came inside, the savory smell of roasted sweet potatoes tickled their noses.
“You played a lot? Hurry up and go change your clothes.”
Having changed into fluffy clothes, Seoeun explained to her mom in an excited voice all about playing outside with Oppa. Then, sipping warm cocoa, she smiled happily at the sweet taste of the roasted sweet potatoes.
Seoha took in all these sights, filling his eyes with them so he would remember this joyful day for a long time.
*Will Seoeun forget today’s events when she grows up?*
As he grew older, Seoha came to realize that he was different from ordinary people.
He possessed extraordinary memory and had never experienced infantile amnesia, which usually sets in around age four.
He could understand concepts at a glance that even adults struggled with.
Now he felt he knew what the people who placed expectations on him wanted.
But Seoha was simply happy in this moment.
He thought that even if Seoeun forgot today’s events later on, he would tell her about them again and again.
* * *
“Oppaaa! Don’t go!”
The year turned, and in January,
Seoha received his KMO second-round pass notice, and a letter instructing him to enroll in winter school arrived at the house.
“Momaaa! I’m going too. I’m going with Oppaaa!”
Seoeun grabbed her Oppa’s clothes and wouldn’t let go.
The couple made troubled expressions at Seoeun’s wailing, as if she would never see him again in her entire life.
“Seoeun, Oppa will be back in two weeks. He’ll come back after you sleep just fourteen nights, okay?”
Miyeong tried to soothe Seoeun affectionately.
“Noooo! Seoeun is going with Oppaaa too!
Seoeun’s cries filled the house.
She was a pitiful sight, gripping Seoha’s shirt tightly with her face covered in tears and snot.
“Seoeun…”
Seoha choked up.
Since birth, the two had never been apart for long.
“Wait just a moment.”
Seoha took out a small box from his bag.
It was a small duck plushie he’d bought from a souvenir shop not long ago. Its yellow fur and orange beak looked cute.
*Good thing I prepared this just in case.*
“I bought this to give to you, Seoeun…”
Seoha lowered himself to meet Seoeun’s eyes.
When he placed the duck plushie in her hands, Seoeun’s crying stopped. Then she opened her wet eyes wide and looked at Seoha.
“Duck?”
“Yeah! If you play with him, I’ll be back soon. I promise.”
Seoeun held back her tears and held out her tiny pinky finger.
* * *
The KMO winter school was held at KAIST, just like the second-round exam.
A rare event where prodigies selected from across the nation gathered in one place.
Vrooooom—
A high-end German sedan smoothly stopped in front of the dormitory. The area was already lined with expensive cars.
Clack.
A girl neatly dressed in a school uniform opened the heavy car door and stepped out.
Glossy black hair, and a face that was pure but looked stubborn.
Hooo.
Sujeong took a deep breath.
The area around the dormitory bustled with students and parents.
Most were familiar faces.
Sujeong thought they were tenacious connections stretching back to elementary school.
After putting their luggage in the dorm rooms, one by one the guardians departed.
Sujeong waved to her departing father and then headed toward the classroom, the designated meeting place.
Slide.
Opening the door and entering, she saw an expansive blackboard.
Four huge blackboards were joined together side-by-side as one.
Fortunately, rails were installed above and below, so they looked usable even without a ladder.
Glance.
Sujeong looked around. And then walked straight toward one side.
“You’re here?”
Before the other could answer, she pulled over a chair and sat in the seat beside him.
The scent of shampoo wafted from hair that had been washed not long ago.
“Hello.”
A pleasant voice.
Seoha didn’t show any of the nervousness or excitement that would naturally be expected from someone experiencing this for the first time.
He just kept looking around as if the large lecture hall were fascinating.
Sujeong was slightly peeved by Seoha’s relaxed attitude.
As the hour arrived, students began entering one by one.
Sujeong tossed out a remark as if casually.
“Go Changseok, third-year high school. First place in all of Jeju Island.”
When Seoha looked at her with questioning eyes, Sujeong gestured toward one side with her gaze.
A student of small stature and thin build was sitting quietly.
A neat hairstyle and thick horn-rimmed glasses that screamed model student. He already had a notebook and pen at the ready.
“Over there is Seo Jiye, first place in Busan.
Physics is her specialty more than math, but it looks like she’ll be going to the IMO this year.”
Sujeong grumbled that there were more competitors now.
They were all people whose names appeared on the top-twenty math list she kept in secret.
While explaining the key figures, Sujeong’s face scrunched up when she saw someone. Then she quickly turned her head.
But the other person had definitely spotted her.
“Yo! Im Sujeong! Long time no see.”
The other person strode forward without hesitation.
Tall height, fair skin, gentle eyes, and a solid build.
Seoha thought he was extremely handsome.
“Got it, now go away!”
Sujeong waved her hand at him as if disgusted.
But the other person smirked and brushed it off lightly.
“Oho! So this is the kid, right? Yu Seoha.”
Seoha stood up and bowed his head politely.
“Hello.”
“I heard about you from the hyungs. They said they took a beating because of you? Nice to meet you! I’m Seong Jihun.”
“I’m Yu Seoha.”
Wherever he looked, there was a crowd of unfamiliar faces.
Seoha thought it was fortunate that at least Sujeong was there.
“He came from the same gifted academy as me. He probably placed first in the Gyeonggi-do competition this time.”
In recent years, high schoolers’ Olympiad results had not been good.
Perhaps as a counterbalance to that, Sujeong’s generation had many outstanding talents.
Jihun was one of them.
“Is that all you have to say? You should say he’s your rival.”
The two had been famous prodigies among their peers for a long time.
“I don’t keep company with losers who couldn’t even make it to the IMO.”
At Sujeong’s words, Jihun smiled awkwardly.
“Well, I was a bit like that back then? I was so shocked that I studied for the first time in my life without anyone telling me to. And then I ranked first right away. See? That’s me.”
“Yes, yes, I’m sure. I only compete at the national level, so I don’t pay attention to local first places.”
She spoke that way, but Sujeong was quite wary of Jihun.
At Sujeong’s cold reaction, Jihun clicked his tongue and sat down at the next desk over.
Soon the classroom grew quiet.
As the students took their seats, tension filled the room. On everyone’s face was the determination to survive until the final six and be selected for the IMO.
Slide.
The door opened and a middle-aged man entered.
Gray hair, a kind face, a professor with a composed demeanor.
“Hello. I am Professor Bak Cheolmin from the Department of Mathematical Sciences.”
Professor Bak stood in front of the blackboard and looked around at the students.
“Since you are all math prodigies from across the country, I suppose a lengthy introduction isn’t necessary. I will be with you for the next two weeks.”
The professor wrote the date small in the upper corner of the blackboard.
“The goal of this winter school is not simply solving problems.
Our goal is to understand the essence of mathematics, the beauty of proofs. I believe your abilities will naturally improve in the process. Of course, at the end, we will select six of you to form the IMO national team.”
A small murmur arose among the students.
*National team.*
What a heart-fluttering ring those words had.
It was an irresistible temptation.
“Now then, let’s begin right away.”
Professor Bak began writing complex formulas using the entire first blackboard.
[Number Theory – Existence of Solutions to Diophantine Equations]
Scritch-scratch.
Inside the classroom, only the sounds of chalk and pens scratching paper could be heard.
All the students concentrated, taking notes and struggling to understand the explanation.
Even Jihun followed the professor’s explanation with a tense expression, unlike his usual self.
Then he looked to the side.
‘Hm?’
Yu Seoha was staring at the blackboard with a blank expression.
His notebook was open but blank.
His hands held nothing.
‘Even if he’s good, I guess he’s still an elementary schooler after all? He probably can’t follow the high-level concepts yet.’
Jihun quickly erased Seoha from his mind. The proof he was currently working on was too difficult to spare concern for others.
But Seoha was thinking something else entirely.
*Why is the professor using that method?*
A much simpler and more elegant proof had already come to mind in Seoha’s head.
It was merely logic that the other students would be unable to understand.
*If I used elliptic functions, I think I could prove it much more cleanly.*
Unable to contain himself, Seoha eventually began verifying his own proof in his head during the lecture.
Professor Bak finished his long explanation and looked around at the students.
“So far, this is the classical approach. Does anyone have any questions?”
Silence.
At that moment, Professor Bak’s gaze stopped on Seoha. He was the only student not taking notes.
“Yu Seoha?”
Startled at being suddenly called upon, Seoha straightened his body abruptly.
“Yes?”
“You aren’t taking notes. Is there some kind of problem?”
Most people in the classroom had only heard the name Yu Seoha; today was the first time they had seen him in person.
The students looked at Seoha with gazes mixed with various emotions.
Seoha stammered, not knowing what he should say.
Sujeong wore an expression that said this was a headache.
She let out a sigh and pressed her hand to her forehead.