The text message on my screen was as clinical as a system status report.
Danoh:Thanks. You worked hard on the core, Hanbin-ah. Sleep well.
I stared at the "Hanbin-ah" for a long time. It was the only part of the message that didn't feel like a professional courtesy. I wanted to reply. I wanted to tell her that I hadn't slept in forty-eight hours, that the coffee in my veins felt like battery acid, and that seeing her through a window with Sunho had hurt more than the punch I took in the alley.
But I didn't. I locked my phone and let the darkness of the dorm room swallow me. Some variables are better left unassigned until the system is stable.
The next morning, I wasn't at the university. I was standing in the polished, suffocatingly quiet hallway of Harin's prestigious high school.
Our parents were busy with the post-holiday rush at the shop, and my eldest brother, Hyuk-hyung—was at a corporate seminar. When the school called saying a "guardian" was needed immediately for an incident involving Jeon Harin, I was the only one left to answer the call.
I was wearing a black hoodie and jeans, looking more like a runaway than a guardian. As I stood outside the Dean's office, I felt a familiar simmering irritation. Harin was a firecracker, but she usually knew how to keep her fuse dry.
I pushed the door open.
Harin was sitting in a plastic chair, her arms crossed, looking remarkably unrepentant. Across from her sat a boy about her age, holding an ice pack to a very swollen, purple eye.
"Jeon Hanbin-ssi?" the Dean asked, looking at my ID. "Thank you for coming. Your sister decided to use her martial arts training on a classmate today."
"He was being a jerk," Harin muttered, her eyes flashing. "He was picking on the girl who sits in the back. I told him to stop. He didn't. So, I assisted him in stopping."
I looked at the boy. He flinched under my gaze. I might have been exhausted, but I still carried the "Ice Prince" aura of SNU.
"Is this true?" I asked the boy, my voice low and cold.
The boy looked at me, then at Harin, and finally at the Dean. "Yes. I... I said some things I shouldn't have. I didn't think she'd actually punch me."
"In our family," I said, leaning forward slightly so only the boy could hear, "we don't start fights. But we definitely finish them. You're lucky it was my sister and not me."
The Dean cleared his throat. "Since the provocation was confirmed, we will stick to a warning for both parties. But Harin-ssi, violence is never the answer."
After ten minutes of paperwork, we were finally ushered out. I walked toward the school gate, Harin skipping beside me as if she hadn't just narrowly avoided suspension.
"You're not going to tell Eomma, right?" she asked, tugging at my sleeve. "Or Hyuk-oppa? He'll tease me for the rest of my life."
"It's a secret," I said, sighing. "But Harin, next time, use your brain before your fists."
"Harin! Is that you?"
A voice called out from the school courtyard. I turned to see a tall, lean high schooler running toward us. It was Doyoon—Danoh's younger brother. He skidded to a stop, his eyes wide as he looked at Harin, then at me.
"Hyung! What are you doing at my school?" Doyoon asked, bowing quickly to me before turning to my sister. "Harin! I heard what happened. You punched that bully! That was incredible! You're seriously the coolest girl in this district."
Harin went slightly pink—a rare sight. "It was nothing, Doyoon. He was annoying."
"Nothing? You're like a K-drama protagonist!" Doyoon's eyes were sparkling. He turned to me, his expression full of respect. "She is amazing. I've never seen anyone move that fast."
I stood there, processing the data. The girl with the quadratic equation line. The girl whose brothers would break his legs.
I looked at my sister, who was trying to act "cool." Then I looked at Doyoon, who was looking at her like she was a goddess.
"Doyoon-ah," I said, my voice dangerously calm. "Are you the one who told a girl she was like a quadratic equation?"
Doyoon froze. He looked at me, then at Harin, then back at me. "Wait... Harin is your sister? The sister?"
"The one whose brother would break your legs," I confirmed, stepping closer.
Doyoon turned pale. "Hyung... you... you go to the gym, don't you?"
"Every day," I lied. "Why do you ask?"
"Harin told me... she said if I ever bothered her again, her older brother would personally dismantle my skeletal system," Doyoon swallowed hard. "I thought she was exaggerating. But seeing you here, Hyung... in the flesh..."
I felt a sudden urge to laugh. The world was too small.
"I'm hungry," Harin announced. "Oppa, since you're here and you're not telling Eomma, you have to buy us lunch."
"Us?" I asked.
"Doyoon helped me find the Dean's office," Harin lied easily. "He deserves a meal."
I looked at Doyoon. He looked terrified of me, but he also looked like he really wanted a burger.
"Fine," I said. "Let's go. But Doyoon-ah? If you ever use a math pun on my sister again, I won't need a gym to do what she promised."
Doyoon gave me a shaky thumbs-up. "Understood, Hyung. No math. Only respect."
We sat in a booth at a nearby burger joint.
"So, Hyung," Doyoon said, his mouth full of fries. "How is the project going? Noona says you're a 'Coding God.' She says the project would have crashed without you."
My heart did a strange, painful stutter. "She said that?"
"Yeah. She talks about you a lot," Doyoon said. "She says you're the most reliable person she knows. Even more than Sunho-sunbae."
I looked out the window. Reliable. Coming from her, it felt like a title.
"Sunho is... a good senior," I said.
"He's okay," Doyoon shrugged. "But you, Hyung... you're real. Harin says you're scary, but you're the kind of guy who actually shows up."
I looked at my sister. She caught my eye and gave me a small, knowing nod. She knew I was an idiot when it came to Danoh.
"Eat your burger, Doyoon," I said, pushing my extra box of chicken nuggets toward him. He was a cute kid. A bit of a disaster, but a good soul.
I pulled out my phone as we walked back to the cars.
Me:I met Doyoon today. He's a handful, but he's a good kid. Tell him to work on his pick-up lines.
I didn't wait for a reply. For the first time in two weeks, the system felt like it was finally back online.