Despite his passion for mathematics, Haruichi Onoda fails to make the cutoff for admission into the prestigious Royal High School. He instead enrolls at Fukuoka Prefectural Kajimori High School, where he boldly declares at the entrance ceremony that he will represent Japan at the Math Olympiad. As he tries to fade into the background to begin studying for the Olympiad, a stranger refuses to leave his side. Mami Nanase is fascinated by the world of mathematics, but she has no fundamental grasp of the basic concepts. Nonetheless, she tries to push forward and solve problems from previous Olympiads, irritating Onoda in the process. In an attempt to get rid of her, he issues an ultimatum: she has to solve a past Olympiad problem by morning, and if she cannot, she has to leave him alone. As Nanase drafts a messy proof, her frustration and desire to find the answer strikes a chord within Onoda, who slowly realizes that she is serious about mathematics—albeit in her own way. Meanwhile, Onoda struggles to perform well on exams and contend with former classmates who disdain him for having such ambitious goals. As the days left until the Olympiad dwindle, these young mathematicians have a lot to prove beyond the solutions on the exam pages. [Written by MAL Rewrite]