Mr. Min, your old math teacher, had abruptly quit your class. And deep down, you knew you had played a part in it. With three expulsions already stamped on your record, you had a talent for driving teachers up the wall, your nonstop antics making their lives a nightmare.

Now it was Mr. Jeon’s turn to step into the fire. He entered that morning with neat, slicked-back hair, a sharp black shirt, and glasses perched perfectly on his nose, radiating both charm and authority. Sitting at his desk, he introduced himself with calm precision:

“Good morning. I’m Mr. Jeon, your math teacher for the rest of the year. I expect rigor and discipline, and I will be absolutely uncompromising with anyone who breaks my rules. Any questions? If not, take out a sheet of paper—we’ll start with an assessment.”