I spent the rest of the evening in a state of mild psychological shock.
The pieces of the puzzle were clicking into place, and the resulting image was mortifying. Doyoon had confessed to a girl whose beauty was "like a quadratic equation." That girl's brother had threatened to break Doyoon's legs. And that brother… was Hanbin.
My brother tried to flirt with Hanbin's sister. The sheer statistical improbability of it made my head spin. I barely slept, imagining the scene at the burger joint: Hanbin, with his "Ice Prince" glare, sitting across from my dorky, over-enthusiastic brother. I felt like I owed Hanbin an apology that spanned the length of the Han River.
The next morning, the department was electric. The project results were finally up. As expected, our Major Unit had swept the top spot with a perfect score. Jiyoon was cheering, and Sunho-sunbae was surrounded by a swarm of juniors asking for his "secrets to success."
But I wasn't looking at the grades. I was looking for the black hoodie.
I found him near the vending machines in the quiet corridor leading to the server room. He was staring at a can of black coffee as if he were trying to debug its existence.
"Hanbin," I said, catching my breath as I reached him.
He looked up. His eyes were still tired, but the sharpness was there—that focused, intense gaze that always made me feel like he was reading my source code.
"Danoh," he acknowledged.
"I am so, so sorry," I blurted out, bowing slightly. "I just realized it last night. The girl Doyoon was bothering... the 'quadratic equation' girl... that was Harin, wasn't it? Your sister?"
Hanbin didn't laugh. He didn't even smile. He just leaned back against the vending machine, crossing his arms over his chest. "She told me he was persistent. I didn't realize it was your brother until I saw him yesterday."
"I'll talk to him," I promised, my face heating up. "I'll tell him to stay away. I'm so embarrassed that he's been a nuisance to your family. He doesn't know when to quit, and his pick-up lines are... well, you heard them."
I expected him to agree. I expected him to say something about how Doyoon needed to focus on his studies or how Harin was too young for such nonsense.
Instead, Hanbin shifted his weight, his expression remains cool and unreadable.
"Don't bother," he said.
I blinked. "What?"
"I've already decided I like him," Hanbin said. His voice was flat, devoid of emotion, as if he were stating a mathematical fact like 1+1=2.
I stared at him, completely lost. "You... you like him?"
"He has a good spine," Hanbin continued, his eyes drifting toward the window. "He didn't run when he realized who I was. And Harin... she doesn't punch people she actually dislikes. She only hits the ones who are worth the effort of an interaction."
My jaw practically hit the floor. This was Hanbin-logic at its finest—twisted, protective, and strangely profound.
"So," I stammered, "you're saying...?"
"He has my permission," Hanbin said. He looked back at me, his gaze freezing me in place for a heartbeat. "He's a good kid. If he wants to keep trying, I won't be the one to stop him. He's passed the first layer of security."
Before I could process the fact that Hanbin had just "cleared" my brother to pursue his sister, he straightened up. He didn't wait for my reaction. He didn't stay to chat about the project or the A+ we had just received.
"I have a lecture. See you in the lab, Danoh-ya," he said.
He turned and walked away, his stride long and confident. He left me standing by the vending machines, clutching my bag and trying to figure out how the world had turned upside down.
Hanbin—the boy who barely let anyone into his own circle—had just opened the gate for my brother. And he had done it with the most "Hanbin" attitude possible: cold, detached, and utterly certain.
I watched his back until he disappeared around the corner. A small, shaky breath escaped me. It wasn't just Doyoon who had passed a "security layer" today. I felt like, in his own silent way, Hanbin was telling me that our families weren't just two separate systems anymore.
They were starting to merge.