April 18, 2025 | Seoul, South Korea
Rain kissed the rooftops like it had a secret to tell.
Outside the library windows, the world blurred in shades of gray—but inside, time had stopped. Or, perhaps more accurately, time was about to begin again.
Park Seo-jin sat alone at the back of the university library, surrounded by stacks of old physics journals, her fingers absently curled around a lukewarm cup of coffee. She wasn't reading. Not really. The words were there, printed and defined, but they didn't sink in. Her mind had drifted back—again—to the boy with the soft eyes and the quiet sadness.
Kim Tae-joo.
He would've turned twenty-eight this year.
He should've.
But he died two years ago—his life cut short by something no one could name and no one could understand. Everyone called it an accident.
Seo-jin knew better.
Because she had loved him.
From the moment she first saw him. And even long after he was gone.
He had been her first heartbreak… and her biggest regret.
The rain continued tapping at the glass like an old memory, and somewhere between the silence and sorrow, a sharp pain struck behind her eyes. She blinked, once—twice—and the room tilted. The floor vanished beneath her. Her fingers opened, dropping the coffee.
And then everything went white.
She woke up gasping.
Not in the library.
Not in 2025.
But in her childhood bedroom.
Surrounded by posters of old K-pop idols, a pink backpack, and a calendar that hadn't hung in years.
Seo-jin scrambled out of bed and ran to the window.
Snow was falling gently outside.
She stared at the date written on the corner of the old paper calendar.
January 1, 2014.
Her hands trembled. Her heart thundered.
And then she whispered, "No way… this isn't real."
But it was.
Because seconds later, a younger version of her mother shouted from the kitchen.
"Seo-jin-ah! Wake up! You're going to be late for your first day back at high school!"
Time had rewound.
And she had been given another chance.
But this time, Seo-jin wasn't going to let fate decide what happened.
This time, she would protect Tae-joo.
Even if it meant changing the entire world.