Rule Zero [Professor×Student]

Chapter 1

Chapter 1: Rule Zero

The café obeyed its own quiet laws.

Steam rose in soft spirals from porcelain cups, tracing invisible sentences in the air before vanishing. The low murmur of conversation blended with the hiss of the espresso machine, a steady rhythm that made time feel slower, more deliberate. Morning light spilled through tall windows, catching on polished wood tables and the faint dust that floated like reluctant thoughts.

At the table by the window sat a man who looked as though he belonged to this calm.

He was tall, his posture straight without being rigid, as if discipline had long ago become habit rather than effort. A pair of thin-framed glasses rested neatly on his face, sharpening eyes that were already attentive. His features were striking but restrained—handsome in a way that did not demand attention, only earned it after a second glance.

In front of him lay several textbooks, stacked with careful precision. Their margins were marked with notes written in a narrow, orderly hand. Between the books and a cup of black coffee sat a croissant, golden and untouched, flakes scattered like small casualties across a white plate. It had been there for some time.

He wore an inner suit—dark, tailored, understated—with a tie knotted perfectly at his collar. No wrinkles, no looseness. Everything about him suggested control, not the harsh kind, but the quiet sort that comes from knowing exactly where one stands. A university professor, unmistakably so. Not only because of the books, but because of the way he read them: patiently, deliberately, as if every sentence deserved respect.

He turned a page.

The movement was calm, steady, practiced. No rush. No distraction. Even the noise of the café seemed to bend around him, lowering itself out of courtesy. When he paused, it was not because his attention drifted, but because he was thinking—truly thinking—eyes unfocused, gaze fixed somewhere just beyond the glass, where the street unfolded in muted motion.

Students passed outside, laughing, arguing, alive with urgency. He did not look at them, yet it was clear he understood them. He had once been them. Perhaps, in some way, he still was.

The croissant remained untouched.

Rule Zero, he believed, was simple: observe before you act. Listen before you speak. Understand before you judge. It was not a rule written in any textbook, but it governed everything that mattered. Especially people.

He lifted the coffee cup, took a slow sip, and set it down exactly where it had been. His reflection briefly appeared in the dark surface—calm eyes, composed expression, a man who carried certainty without arrogance.

Soon, he would leave the café. Soon, he would step into a lecture hall and command a room without raising his voice. But for now, he remained still, surrounded by warm light and quiet noise, a professor at rest, preparing for a day that would test whether Rule Zero could survive the world beyond this table.

And whether he could.

Across the city, far from the café’s quiet order, chaos was already awake.

The house was loud in the way only students’ houses could be—music leaking from a speaker with no clear owner, laughter bouncing off walls that had seen too many late nights, and the unmistakable smell of instant noodles mixed with burnt toast. Books were everywhere, though rarely where they were meant to be. On the living room floor, four students had claimed the space as their own.

At the center of it all was William.

William the Sharp, they called him—not because he followed rules, but because he cut straight through them. He sat sprawled across the couch, one leg draped over the armrest, a grin permanently threatening his face. His eyes were bright, restless, always searching for something to poke, challenge, or disrupt. Stubborn to the core and famously naughty, William was a menace in any room unlucky enough to contain him.