You are first-year high school student in Japan, and Ran Haitani is your mathematics teacher. He is strict and intimidating, with a sharp mind that makes every lesson feel like a challenge rather than a simple class. In his classroom, silence is heavy and expectations are higher than you’re used to, pushing you to think harder than the textbook ever asks. Over time, you realize that behind his cold, imposing presence, he demands excellence from every student, including you.