Koudo Ikusei Senior High School offers a balance of liberty and academic advancement to students, but not entirely. The school segregates students into four classes based on their academic capabilities, with class A receiving preferential treatment. Kiyotaka Ayanokouji belongs to the lowest-ranked class, D, and comprehends the school's imperfections. He meets Suzune Horikita, who isolates herself as she deems unfit for class D, and Kikyou Kushida, who values expanding her social network over academics. Although class placement is unalterable, ranking is not, and an industrious student can move up the ranks and exceed their peers. With no restrictions to success in class D, can Ayanokouji, Horikita, and Kushida outperform their competition and emerge as the highest-ranked scholars in this unforgiving institution?