Kyung-eun hesitated for a moment before blurting out a question.

“What are you doing?”

Was she pretending not to notice what he was doing even though she had been watching him all along? Uncertain herself, Kyung-eun fidgeted with the fingers she held behind her back.

“…Studying.”

He was an incredibly taciturn child. Despite the fact that the boy had hardly ever spoken with friends of the opposite sex—there were almost no girls his age at the orphanage to begin with—he had never freely chatted and laughed with his peers at school, so this reticence was inevitable. But Kyung-eun did not know this, nor did she plan to stop there.

“You like books, don’t you?”

Everyone knew the boy liked books, but Kyung-eun was not merely confirming his interest in them.

“Yes, I do.”

It was his facial expression she was curious about. From the time he arrived at school to the time he left, the boy’s expressions were few. It was no wonder he was nicknamed ‘Plaster’ not for his handsome face, but for his emotionless expression.

Still, when talking about books, even an inexperienced child could detect the slight changes in his face. Kyung-eun felt as if she had unearthed a great secret.

“Would you like to come and see the books at my house?”

The sudden invitation left both speechless, both the puzzled boy and the flustered Kyung-eun.

“My sister and brother like books, so we have a lot. I read a lot too. I thought you might like them. Or should I lend you some?”

As Kyung-eun rambled on, the boy found her demeanor somehow endearing and did not harshly reject her offer.

“It’s hard to go all of a sudden. After school, I need to go home. But I’d appreciate it if you lend me some.”

First graders were not allowed to borrow books from the library, so they had to return them after school. This was always a disappointment to the boy, so he welcomed Kyung-eun’s offer with a smile filled with gratitude. Kyung-eun stared at the boy blankly for a moment, then quickly gathered her senses and hurried back to her seat.

“Okay.”

After leaving a brief reply, Kyung-eun turned away, and the boy shifted his focus back to the problem he had been working on. School was truly a wonderful place. There were kind teachers who gently explained things, stacks of books that detailed unknown facts, and friends who willingly showed kindness. There were also teachers who looked down on him with prejudice, classmates who teased him for not having parents, and kids who sneered at him for not bringing proper supplies, but none of that mattered or bothered the boy. The school life was joyful and happy with plentiful meals and abundant knowledge alone.

After school, the math class was taught by Park Hae-ul, a veteran instructor with over ten years of experience teaching mathematics.

Hae-ul, who had graduated from a prestigious university, had escaped the crisis of youth unemployment through a post-school teacher certification. With substantial private tutoring experience, he initially struggled with teaching elementary students, but after a decade, he had become a veteran, comfortable enough to conduct classes with ease. However, that ease was now disappearing.

“Teacher, is this also a circle? Why?”

Pointing to an elliptical shape, the child looked up curiously, causing sweat to bead on Hae-ul’s forehead. It was difficult to explain ellipses in the elementary curriculum, especially to a child who had just started first grade.

“We said that a round shape is a circle, right? This is also round, isn’t it? Technically, it’s not exactly a circle, but since it’s similar, it can be considered part of the circle family.”

Elementary students often struggle with formal definitions, known to learn better through similar shapes and models rather than technical definitions. For example, instead of the definition ‘a set of points in a plane equidistant from a given point,’ they learn about circles through common shapes like basketballs, globes, and coins.

“If it’s round because it looks like this, is this also a circle?”

The boy pointed to a star shape with smoothed angles. Hae-ul forced a smile while internally scrambling to formulate sentences to explain, to find a solution.

“In this book, it says a circle has a center and a radius. These shapes all have the same radius, but this shape has a long radius here and a short radius there, so isn’t it not a circle?”

Wow, Hae-ul thought to himself. At this point, he knew he had to view this child differently. At least the boy understood the concept of ‘radius’ just by reading, unlike how he would treat other first graders.

“Actually, it might be difficult for you to understand, but shall I explain it in the way your older siblings learn?”

Hae-ul looked around at the other students, who were wide-eyed, curious about how the situation would unfold, thinking it wouldn’t be bad to set some limits. Thus, he began teaching ‘geometry’ in a very typical, mathematical definition.

“A triangle is made by connecting these three points here, here, and here. These three points should not lie on a straight line.”

“Can two points be on the same line?”

“……”

Would the onslaught of questions ever end if he explained what a ‘line’ is?

“Mr. Park must have had a hard time, huh?”

“Don’t even mention it. He was really sweating it.”

Hae-ul picked up some kimchi and frowned as Mijin, a fellow after-school instructor and friend who often laughed at the situation, burst into laughter again. The two instructors, who had started working together at Hyeun Elementary School, had come to a pork spine stew restaurant after their classes to eat dinner and relieve stress.

“Look, I think that kid is a genius. Not just any genius, but a real genius. When he presents in my class, I wonder if he’s really just an elementary student. And he’s only in first grade? It’s unbelievable unless you see it with your own eyes, but it’s happening right in front of me, so I have to believe it.”

Hae-ul downed a shot of soju and handed Mijin a glass of water as she grimaced at the bitterness.

“That kid, at first, he was just like the other kids. Quiet, not talking much, right? But then, one day, he started throwing out questions, and now he’s like a porcupine. Relentlessly sharp.”

“My class too. Wow, I had no idea the kid could talk like that. Debating? Give him another year or two, and he could probably pass the college entrance exam. Half-joking.”

“That’s a bit much, isn’t it?”

“Yeah, maybe a bit much, right?”

They laughed and clinked their soju glasses. Then they dug into the bubbling stew to satisfy their hunger.