The smell of chalk dust hit Jang Taesan first, sharp and dry, mingling with the faint tang of ink from ballpoint pens and the musty scent of old textbooks. He blinked against the harsh fluorescent lights buzzing overhead, his vision swimming as the world came into focus.
When the blur cleared, his heart slammed against his ribcage.
Wooden desks, scratched and worn, stretched in neat rows before him. Uniformed teenagers hunched over notebooks, some scribbling furiously, others whispering or doodling. A blackboard loomed at the front, covered in messy equations scrawled in white chalk. Faded posters lined the pale green walls, one catching his eye with bold Hangul:
"Countdown to CSAT: 120 Days Remaining."
Taesan's body froze. His breath hitched, coming in short, uneven gasps. Slowly, he lowered his gaze to his hands.
No scars. No callouses. No trace of the years spent gripping batons as a security guard or punching numbers into a failing stockbroker's terminal. His fingers were lean, smooth, almost delicate—hands of a seventeen-year-old.
"No…" The word slipped out, a hoarse whisper, barely audible.
The classroom buzzed around him—boys joking about a soccer match, girls giggling over a shared note, the rhythmic scratch of pencils on paper. The sounds were achingly familiar, like a song he hadn't heard in over a decade. He knew these voices. These faces.
"Are you okay, Taesan?"
The voice came from his right, bright and teasing. Taesan turned, his movements sluggish, as if underwater, and stared.
The boy beside him wore the same navy school uniform, his tie sloppily knotted, his grin wide and boyish. Han Do-jin. A classmate Taesan hadn't seen since high school. A friend who had died in a car crash during their first year of college, a tragedy that had haunted Taesan for years.
His throat tightened, words barely forming. "…Do-jin?"
The boy tilted his head, eyebrows raised. "Uh, yeah? Who else would it be, man? You look like you saw a ghost."
The casual words hit like a freight train. The room tilted, and Taesan shot to his feet, his chair scraping loudly against the floor. Heads turned, classmates muttering in annoyance or amusement.
"What's with him?"
"Did he hit his head or something?"
"Maybe he didn't study and finally snapped."
Their laughter clawed at his nerves, but Taesan barely registered it. His eyes darted across the room, taking in every detail—the rickety ceiling fans creaking lazily, the chipped paint on the walls, the clock above the blackboard ticking with cold indifference.
The date.
His gaze locked onto the calendar pinned at the corner of the board.
July 12, 2008.
His knees buckled, and he gripped the edge of his desk to steady himself. His mind screamed, racing toward the impossible truth.
He was seventeen again.
Memories flooded in, sharp and merciless.
The 2008 financial crash, when the stock market bled red and his dreams of becoming a top stockbroker crumbled. The humiliation of watching his colleagues distance themselves, one by one, as his trades failed. The years that followed—odd jobs, debt collectors knocking, the quiet pity in his family's eyes as they whispered about the "fallen genius." In the end, he'd been reduced to a security guard, patrolling empty buildings, invisible to the world.
He had swallowed it all. The regret. The loneliness. The weight of failure.
And then, that final night.
A child's scream piercing the air. Headlights blinding him. Tires screeching on asphalt. He remembered the terror in the little girl's eyes—Emma Kim, frozen in the street as a car barreled toward her. He remembered his body moving on instinct, shoving her out of the way.
The impact.
The pain.
The darkness.
He had died.
He was certain of it.
Yet here he was.
Back in his youth. Back in the days before his life unraveled.
Taesan's grip on the desk tightened, his knuckles whitening. His chest heaved with ragged breaths, his pulse thundering in his ears.
"Taesan, are you paying attention?"
The sharp voice snapped him back. He turned to the front, where the math teacher, Mr. Lim, stood glaring, chalk in hand, his glasses glinting under the lights. Lim looked exactly as Taesan remembered—stern, sharp-eyed, the terror of every student who dared slack off. A man who, in his past life, had succumbed to liver cancer years later.
"You," Lim barked, tapping the blackboard with his chalk. "Solve this problem. Now."
Snickers rippled through the classroom. Min-soo Kang, the class bully with a permanent smirk, leaned back in his chair, arms crossed. "Bet he screws it up again," he muttered, loud enough for everyone to hear.
Heat flared in Taesan's neck, a mix of embarrassment and defiance. In his past life, he'd fumbled this problem—a complex calculus equation that had taken him twenty agonizing minutes to half-solve, earning Lim's scorn and Min-soo's mocking laughter. He'd been average then. Forgettable.
But now…
He stood slowly, steadying his trembling hands. His eyes locked onto the equation scrawled across the board. The numbers and symbols clicked into place instantly, as if lit up in his mind. He remembered this problem. He remembered every problem. Years of studying, failing, and analyzing had burned them into his memory.
Taesan picked up a piece of chalk, its weight familiar yet strange in his youthful hand. The classroom fell silent as he began to write, his movements precise, almost mechanical. Step by step, the solution unfolded—flawless, elegant, complete. He set the chalk down and stepped back.
The silence stretched.
Mr. Lim adjusted his glasses, scanning the board. "…Correct," he said finally, his tone grudging, tinged with surprise.
Whispers erupted across the room.
"When did he get so good?"
"That was fast…"
"Taesan? Seriously?"
Min-soo's smirk vanished, replaced by a scowl that promised trouble later.
Taesan ignored them all. He returned to his seat, his pulse still racing, a faint grin tugging at his lips.
It was real. His memories, his knowledge—they had come with him. This wasn't a dream or a delusion.
The rest of the day passed in a haze of disbelief and quiet exhilaration. Taesan moved through classes like a man possessed, answering questions with unnerving accuracy, recalling every test, every problem set, every mistake he'd once agonized over.
Classmates stared, some with awe, others with suspicion. Even Sophie Leclerc, the half-French math prodigy who kept to herself, cast him a curious glance from across the room, her sharp eyes lingering a moment longer than usual.
But beneath the thrill, his mind churned.
The CSAT was 120 days away—the gateway to Korea's brutal university system. In his past life, he'd choked, scraping by with a mediocre score that shut him out of top schools and set the stage for his downfall.
Not this time.
He knew every question, every trick, every answer. He could walk into that exam hall tomorrow and score perfect.
And beyond that… the stock market.
A shiver ran through him. Every chart, every trend, every boom and bust from the next decade was etched in his mind. He could predict the market like a prophet. He could rebuild everything he'd lost—no, he could surpass it.
He clenched his fists beneath the desk, determination settling into his bones. I won't be a guard again. I won't be a failure. This time, I'll rise above them all.
The final bell rang, and students spilled out into the humid summer air, chattering and laughing.
Taesan lingered, staring at his reflection in the classroom window. The boy looking back was seventeen, but his eyes carried the weight of thirty-one years—years of pain, regret, and hard-earned wisdom.
His lips curled into a determined smile.
"This time," he whispered to himself, "I'll write my own legend."