" The Girl They Called Devil "

Episode 9: The Math Struggle

The car pulled through the tall iron gates of the mansion, rolling smoothly up the long driveway as the golden evening sun painted the gardens in warm light. Mr. and Mrs. Choi were already waiting at the main entrance, stepping forward the moment the engine cut off. Their faces were bright with excitement—today marked Yujin’s very first day at St. Claire Academy.

“So?” Mrs. Choi asked softly, stepping closer as Yujin and Woo-jin climbed out. She adjusted the collar of Yujin’s blazer with loving hands. “How was it, Yujin? Was everything okay? Did you like the school?”

Yujin paused for a second, her expression calm and guarded as always. “It was good,” she replied simply, her voice steady. “The school is big, and the classes are fine.”

Mr. Choi chuckled, patting Woo-jin’s shoulder. “And you? Did you keep an eye on her like you promised?”

“Always,” Woo-jin answered proudly, throwing an arm easily around Yujin’s shoulders. “Everyone already knows she’s my sister. No one dared cause trouble. She handled herself like a queen, honestly.”

They walked inside together, the scent of delicious food drifting from the dining hall. Dinner was served at the long table—plates filled with warm, rich food, nothing like the plain meals she had eaten back at the hostel. They talked about lessons, teachers, and the campus, but Yujin kept her answers short and careful. She smiled only faintly when they spoke to her directly, but deep inside, the same walls remained standing tall. They act like this will last forever, she thought to herself while cutting her food slowly. They treat me like treasure, but I will still watch every step I take. Trust takes time… and I have plenty of it.

Just as they finished eating and were wiping their hands, the heavy front door opened again. A boy stepped in, greeted warmly by the staff. He was tall, lean, and carried himself with the same kind of natural confidence Woo-jin had. He had soft, neat hair, warm bright eyes, and a face so handsome and charming that every girl in school dreamed of getting close to him. This was Han Ji-hoon—Woo-jin’s absolute best friend since childhood. Together, they were known as the school’s pride: both top students, champions in sports, smart, kind, and admired by everyone. Wherever one went, the other followed.

“Sorry to drop by so late!” Ji-hoon said with a bright, friendly smile as he walked into the dining room. “We have that big math test coming up, remember? I thought it would be better to study here together. Quieter than my house.”

“You are always welcome here, Ji-hoon,” Mrs. Choi said warmly. “Stay as long as you like.”

Woo-jin grinned and stood up from his chair. “Perfect timing. Come on up to my room then. We need to finish these chapters or we’ll both be in trouble.”

The two boys headed upstairs, laughing and talking about recent matches and school events, leaving Yujin to go her own way. She climbed the stairs slowly, walking past them to her own room at the end of the hall. She closed her heavy double doors and sat at her large desk, opening her books and notebooks neatly. She told herself she would master everything, just like she mastered survival. History, languages, science—she read through them quickly, understanding every word, memorizing facts easily. She was sharp, and learning came naturally to her.

But then she turned the page and froze.

Mathematics.

Numbers, formulas, shapes, and long, twisted problems stared back at her. Her forehead creased in frustration. She read the question again… and again. Nothing made sense. It looked like a secret code written in a language she didn’t speak. Her jaw tightened. I hate math, she thought bitterly. Why do we even need this? It’s just numbers and more numbers, and they make everything complicated on purpose.

Minutes turned into half an hour. Her notebook was filled with scribbled attempts, crossed-out lines, and wrong answers. She tapped her pen against the paper sharply, irritation growing inside her chest.

Just then, the door opened gently and Mrs. Choi peeked inside. She walked over quietly, seeing the frown on Yujin’s face and the messy work spread out.

“Working hard?” she asked softly, brushing a strand of hair away from Yujin’s face. “Do you understand everything? Or do you need some help, sweetheart?”

Yujin hesitated for a moment. She hated admitting weakness or confusion—it was something she had taught herself never to do. But these questions were impossible.

“I understand everything else perfectly,” she answered truthfully, her tone low. “But… Math. I don’t understand Math at all. It is confusing and strange.”

Mrs. Choi smiled kindly, recognizing the frustration. “Don’t worry. That happens to everyone sometimes. Why don’t you go to Woo-jin’s room? He is studying there right now with Ji-hoon. They are both brilliant with numbers. Go knock and ask them to explain it to you. They will help, I promise.”

Yujin let out a long breath, closing the textbook with a thud. She gathered her notebook and papers, holding them tight against her chest. Fine. I will ask. But only because I need to know it, she told herself firmly.

She walked down the hallway until she reached Woo-jin’s room. Through the open door, she could see the two boys sitting by the large window, books open, papers scattered, pens in hand, chatting while they worked. She knocked once, sharp and clear.

“Brother Jin? Can I come in?”

Woo-jin looked up immediately and beamed at her. “Come in, Yujin. Door’s open.”

She stepped inside, and Ji-hoon lifted his head from his notes. His eyes widened slightly as he looked at her properly. He had heard all the stories and knew Woo-jin now had a sister, but seeing her up close was different. She was beautiful in a rare, striking way—like a dark pearl, mysterious and glowing. He had seen hundreds of girls trying to get his attention, but none of them carried this kind of quiet power and grace.

“So this is the famous sister everyone is talking about,” Ji-hoon said, his voice soft and friendly, a warm smile tugging at his lips. He looked at Woo-jin. “You weren’t lying. She is really very cute.”

Woo-jin laughed proudly, leaning back in his chair. “Told you! She is my cute little sister, even if she looks serious all the time. She’s the best.”

Yujin ignored the compliments, standing straight and placing her papers flat on the table between them. Her expression remained cool and serious. “I don’t need compliments. I need help. I cannot solve these questions. They don’t make sense to me.”

Woo-jin leaned forward to look at the problem. “Let me see. These are easy ones, Yujin. Watch carefully.”

He took a pen and started explaining step by step, speaking clearly, breaking the formula down slowly. He went through it once… twice… three times.

Yujin listened, her eyes tracking his writing, her mind working fast. But the way he described it was too fast, too messy, too mixed with shortcuts he already knew. She shook her head firmly. “No. I still don’t get it. It is tangled up.”

Woo-jin started again, slower this time, repeating the same words. “Look—if you move this here and multiply by that, you find the answer. See?”

Five minutes passed. Ten minutes. Yujin shook her head again, just as confused as before.

Woo-jin groaned dramatically, throwing his hands up in the air, eyes wide as if he was about to cry from frustration. “Yujin! Why do you not understand? This is the simplest question in the whole book! Even a beginner would get it in one try! How is it possible?”

“It is NOT simple!” Yujin argued back, her tone rising slightly, cheeks flushing a little with annoyance. She pointed sharply at the textbook. “It is very hard! It looks like a puzzle designed to trick people! Solve it again for me, and explain it like I know absolutely nothing!”

Ji-hoon watched the two siblings bickering back and forth with amusement, holding back laughter. Then Woo-jin turned to him, defeated, wiping pretend sweat from his forehead.

“Ji-hoon, you take over. Seriously, I give up. I think the way I teach confuses her brain more. She definitely won’t understand my method. Your way is calmer and clearer. You try—if you make her understand, I owe you a meal at the best restaurant in the city.”

Ji-hoon chuckled and slid closer to her side of the table. His attitude changed instantly—he became patient, soft-spoken, and very clear. He didn’t rush. He started from the very basics, drawing small diagrams, using simple words, and turning the numbers into something logical and easy to follow.

“See, Yujin? Think of numbers like soldiers. They have a proper place to stand and a proper order to move. Follow this path… one step… then the next… and you arrive at the answer naturally.”

He went through the explanation exactly two times. That was all it took.

Yujin stared at the work written in front of her. Suddenly, everything clicked into place. The tangled mess straightened out. Her eyes lit up—bright and sharp, clearer than before. A small spark of satisfaction appeared on her face.

“I understand now,” she announced confidently, lifting her chin. She looked at Woo-jin with a slight smirk. “You were wrong, Brother Jin. This is actually a very simple question. You were just explaining it the difficult way.”

For a heartbeat, silence filled the room—then both boys burst out laughing, loud and warm. Woo-jin shook his head, grinning from ear to ear. “Oh really? Now suddenly it’s simple? Only because Ji-hoon saved you! Next time, remember—if I can’t teach you, he is always here to fix my mess.”

Ji-hoon smiled at her gently, closing the textbook softly. “Don’t worry. Math always looks like a monster at first, but once you learn its secrets, it becomes your easiest subject. If you ever get stuck again, just come knock. We won’t mind.”

Yujin gathered her papers neatly, satisfied now, the frustration completely gone. She nodded to them, her manner polite yet distant as always. “Thank you. Both of you. Goodnight.”

She walked out of the room and back to her own bedroom, closing the door softly behind her. She sat back at her desk, ready to practice the problems again on her own. Even though she had laughed and felt light for a moment, her thoughts returned to their usual path as she picked up her pen.

They are kind, smart, and helpful, she admitted to herself. They treat me like family without asking for anything back… or so it seems. But I will keep my eyes open. I will learn everything they teach me—math, skills, strength, and confidence. I will grow powerful enough that one day, no one will ever dare to call me cursed or weak again. And until then… I will play the part of Choi Yujin perfectly, while protecting the dark girl inside who survived it all.