At the back of the room, near the window, Sang-woo sat with his back perfectly straight, tracing formulas in his notebook with neat handwriting. His hair was a little disheveled, as if he had just come out of the library, where he had been sitting for too long studying his high school problems again. The teachers adored him, his classmates were jealous, and he… he just wanted Gi-hun to finally stop kicking him under the desk.

“Hey, Sang Woo,” he whispered, leaning closer, his voice mischievous as always, “if I drop a textbook from the third floor, do you think it will break?”

Sang Woo sighed and did not look up: "It depends on the mass, the shape of the fall, and the angle of the surface. But it would be better if you did not take the risk. It could be dangerous."

“There you go again,” Gi Hong chuckled, lightly touching his shoulder, “you know that I love it when you act smart like that.”

Sang-woo's heart sank slightly. He pretended not to hear. Gi-hoon always did this—laughing, teasing, putting his arm around his shoulders, as if they were just friends. Although sometimes, especially when their fingers accidentally touched, Sang-woo felt his insides freeze.