The coffee tasted quite good as he took a long drink.
As Kang Woo sipped his coffee, he reflected on everything that had happened over the past few days.
At first, everything had felt strange, and adjusting had been difficult. But once he gave up trying to resist, things became easier. After all, even if he insisted that he was Son Kang-woo rather than Kang Woo, no one would believe him. That meant he would have to go on living as Kang Woo, a high school student.
Then there was his encounter with Ma Do-hwan. He would have liked nothing better than to punch the man in the face on the spot, but compared to Ma Do-hwan, he was practically powerless now. Their social standing was beyond comparison. He had no choice but to postpone his revenge until some distant day.
Someday, he would rise to become one of the country's foremost scholars and expose every one of that bastard's misdeeds. To take his revenge, he would have to become the most famous scientist in the country—no, in the world. Now that he had entered young Kang Woo's body and was about to attend a science high school all over again, it was hardly an impossible goal.
Whatever his abilities in other subjects, he was confident that he could become the best in the country when it came to physics. For now, he intended to concentrate on achieving success and set revenge aside.
Since he had been given another life, he resolved to soar even farther this time. He would surpass Son Kang-woo and become a nuclear fusion physicist whose name was known throughout the world.
Let's fly! Farther than ever before!
That was the conclusion he had reached, and the goal he had set for his life.
First, though, if he wanted to succeed, he would have to adjust to high school life.
As he drank his coffee and sorted through his thoughts, he overheard the two girls sitting beside him.
“You see, if you apply the formula like this...”
The cool-looking girl picked up a mechanical pencil and swiftly began writing an answer in the workbook.
“Do you have to use a formula?”
At the question from the cute girl with glasses, she furrowed her brow and fell into thought.
Students learned and grew through discussions like these. It was a pleasant sight, watching them puzzle over a problem together and search for an answer. Once upon a time, Kang Woo had racked his brains over his studies in graduate school in much the same way.
Seeing the two students thinking and debating so earnestly stirred something warm inside him. He could see in them the fresh enthusiasm that had burned out in him long ago.
There had been a time when he, too, had devoted himself to studying, poring over workbooks until his head hurt. Remembering those days made him think, for the first time, that experiencing high school all over again might not be so bad.
And there was something else...
He wanted to test them.
How did students study these days? Just how capable were they? He would be meeting plenty of students from now on, but he could barely contain his curiosity.
'Well, I've never been able to leave a question unanswered.'
Kang Woo quietly rose from his seat and approached the two girls. They glanced at him but paid him no attention, turning back to their problem.
The question they were struggling with was a physics problem. There was no way he would be unfamiliar with his own field.
Noticing his interest, the cool-looking girl frowned and addressed him.
“Who are you? A new student?”
“That's right, but...”
“Are you good at physics?”
“I'm just interested in it.”
When Kang Woo nodded, she pushed the workbook toward him.
“Then have you tried solving this problem?”
She showed not the slightest hesitation. Before he knew it, she had even switched to informal speech.
Kang Woo decided to go along with the two of them. He would have to make friends at school sooner or later, and these girls could be among them.
The moment he examined the problem, his face tightened.
'Why is this so difficult?'
The problem involved rolling a solid cylinder and a hollow cylinder of equal mass down a slide.
It required converting gravitational potential energy into translational and rotational kinetic energy. To solve it, a student needed to understand the concept of the moment of inertia.
The trouble was that the moment of inertia was not covered in middle school—or even in the high school curriculum. Substituting values into the formula would produce the answer immediately, but would students really understand the concept behind it? This was a perfect example of the harmful effects of private-academy entrance-exam preparation.
“I suppose that's what happens when academies push students so far ahead...”
“Huh? What do you mean?”
Both girls were staring straight at him. Kang Woo shook his head.
He might as well find out just how intelligent they really were.
“Did an academy give you this workbook?”
“Everyone goes to an academy these days. Don't you?”
“Hmm. You solved it correctly.”
“Well, you just substitute the values into the formula...”
“Then do you understand what that formula actually means?”
The cool-looking girl could not answer immediately. Her solution was correct, but she could not explain the formula at all.
The concept of the moment of inertia was difficult in itself, and deriving the formula required integration, making it even harder.
She had merely plugged numbers into a formula she knew to obtain the answer. That did not mean she truly understood it. She might receive full marks on a test, but she did not know the underlying principles.
“Do you know what the moment of inertia is?”
“More or less... Do you?”
There was no confidence in her voice. Her academy had probably covered it briefly. She must have encountered it at least once while preparing for the entrance exam. But this approach of memorizing formulas without understanding even the basic concepts only made studying more difficult.
In fact, no question like this would appear on today's diagnostic assessment. It depended entirely on material taught ahead of the standard curriculum.
Kang Woo began a brief explanation.
The two girls' eyes widened at how easy he made it sound.
“Oh, you really do know this!”
The two girls nodded and asked him a few more questions. The fact that they understood immediately showed that they really were clever.
“But... do academies teach things this way? Memorizing formulas blindly won't do you much good.”
At his remark, the cool-looking girl bit her lip and argued back.
“My academy said something different. They told us that if we don't understand something, we should memorize the formula first. We'll figure it out naturally as we keep solving problems.”
“Of course, there's some truth to that. You can't derive every formula from scratch every time you solve a problem. And if you want to do well on exams, sometimes you need to memorize things.”
“Are you good at studying?”
The cool-looking girl sounded irritated, and a wary look entered her eyes.
“Huh? Not particularly...”
Her brow furrowed even more deeply.
“What's your name?”
“Me? Kang Woo. What about you?”
“I'm Son Cha-hee. This is Yoon Su-a.”
The cool-looking girl with long hair was Son Cha-hee, while the cute, short-haired girl with glasses was Yoon Su-a.
Just as Kang Woo tried to commit their names to memory, faint writing appeared above the girls' heads. He rubbed his eyes and stared blankly at the empty air.
'What the hell is this?'
Above Son Cha-hee's head were the words...
- Son Cha-hee, Mathematics B, Physics A, Chemistry A, Biology B, Earth Science B.
And above Yoon Su-a's head...
- Yoon Su-a, Mathematics C, Physics B, Chemistry B, Biology B, Earth Science C.
The letters hung there as though on signboards.
“What? Is something wrong?”
Uncomfortable with the way he was staring, Son Cha-hee questioned him with an annoyed expression.
“N-no. It's not that...”
The writing above the girls' heads gradually faded away. But when Kang Woo tilted his head, recalled what he had seen, and stared intently at Son Cha-hee again, the letters became clear once more.
In truth, he was less curious about why he could see the writing than about what it meant.
'Son Cha-hee has an A in physics? Isn't A practically the highest rating?'
Yet Son Cha-hee's current ability in physics could hardly be called A-level. After all, she did not properly understand the moment of inertia, a concept taught in introductory university physics.
While Kang Woo was lost in thought, a male student approached their table. He was tall, with an arrogant expression. Carrying himself with the swagger of someone who looked down on the rest of the world, he noisily sipped juice through a straw from a disposable cup.
“Hey! Cha-hee! Long time no see!”
“Huh? Lee Min-chan? What are you doing here?”
“Looks like some guy's bothering you. Want me to rescue you?”
After taking a sip of juice, Lee Min-chan glanced at Kang Woo. His expression made it clear he was half joking. Suddenly cast as some fellow drooling over a pretty girl, Kang Woo let out a disbelieving chuckle.
“It's nothing like that. There was a problem I didn't understand...”
Son Cha-hee hurriedly closed the workbook, but Lee Min-chan snatched it away.
Meanwhile, Kang Woo's attention had been captured by Lee Min-chan's sudden appearance.
- Lee Min-chan, Mathematics A, Physics A, Chemistry B, Biology A, Earth Science A.
He could clearly see writing above this boy's head as well.
Those were impressive ratings. Lee Min-chan appeared to be a little more capable than Son Cha-hee. Kang Woo did not know exactly what the letters meant, but if they represented anything meaningful, Lee Min-chan was evidently more talented than Son Cha-hee.
“Heh, heh. Looks like you've lost your touch, Cha-hee. Asking a guy like this for help!”
Son Cha-hee's and Yoon Su-a's faces immediately twisted with annoyance. Lee Min-chan glanced through the workbook and clicked his tongue.
“Wow, you tried solving all of these? You've really been studying like your life depends on it! Hmm, is this the problem?”
“No!”
Yoon Su-a struggled with him, trying to snatch the workbook back.
“Something like this won't be on the test. It's outside the curriculum, isn't it? Even if they do ask about it, they'll only test the concept.”
Son Cha-hee looked even more irritated. Lee Min-chan gave a smug little laugh.
“If it comes up on the test, I'll answer that both cylinders come down at the same speed. Galileo proved it with his experiment at the Leaning Tower of Pisa, didn't he?”
“But that's not the correct answer.”
“At the middle school level, you don't consider friction. Without friction, the cylinders won't roll, so there's no need to worry about moments of inertia or anything else. Haha!”
Son Cha-hee could not argue back. He had cleverly sidestepped the intended point of the question, which suggested that Lee Min-chan probably understood the moment of inertia.
“So do you understand it or not?”
“I'm telling you, that isn't important.”
“Well, it is to me! It sounds like you don't know. Want me to explain it?”
Son Cha-hee glared at him and recited the concept she had just learned. Lee Min-chan's eyes flickered with surprise.
“Wow! You really have been studying hard! Is it because you want to beat me?”
“Hey! Why would I want to beat you?”
“Heh, heh. No need to deny it.”
Lee Min-chan left the café, noisily sucking the last of his juice through the straw.
Yoon Su-a quietly spoke to Son Cha-hee, who was still fuming.
“Ugh! He's so obnoxious. Min-chan got the highest entrance score, right?”
“I think so.”
“Then you're second?”
“That's what I heard. But I'm definitely going to beat him from now on!”
Son Cha-hee's expression was very dark.
Kang Woo realized that all three students had attended the same academy. It also seemed that Son Cha-hee, the girl in front of him, had lost out to a rival in the entrance examination.
He felt as though he ought to say something comforting, but he was not used to situations like this and could think of nothing to say.
Son Cha-hee angrily gulped down the coffee in front of her, then turned her frustration on Kang Woo.
“And what's with you? I came in second in the entrance exam, so how did you manage to solve that problem better than I did?”
Kids these days were fierce. At a loss for words, Kang Woo merely held up his palms.
* * *
“Haaah!”
He straightened his back, looked up at the ceiling, and resumed his work.
About a hundred folding chairs had been arranged in rows across the spacious auditorium.
“Student! That row's crooked.”
A teacher some distance away pointed at a chair in front of Kang Woo.
“Yes, yes. I know. I know.”
He could not snap at the teacher, nor could he run away. Perhaps today was simply a spectacularly unlucky day.
Kang Woo was currently hard at work lining up chairs in the gymnasium-cum-auditorium.
As for how he had ended up in this situation, a teacher had caught him the moment he finally entered the auditorium after leaving the café.
“Hey, student! Give us a hand.”
“Pardon?”
“We need chairs. Go and bring some over.”
And so Kang Woo had been rounded up along with several other students to carry folding chairs and arrange them in rows.
Because the auditorium was normally used as a gymnasium, they had to bring the folding chairs up from the basement storage room. Kang Woo straightened his back again and stared at the ceiling. He felt like the rabbit drinking from the little spring.
Meanwhile, the two girls who had entered with him were over on the other side, enjoying themselves.