
S01E01 Fermat’s Last Theorem
At Asung High, Yoon Su’s new workplace, she gives a tricky question for students who want to join the math club. While no one in the class got the question right, a correct answer sheet...
For the first time, Yoon Su reveals to Seung Yoo her pain and suffering. Seung Yoo discovers the person behind their love scandal and proposes they stand together and fight. Meanwhile, Ye Rin ends up witnessing a surprising fact and rushes to Noh Jung Ah to tell her about it.
A sexual scandal between a math teacher and a student in a prestigious high school ended in tragedy. 4 years later they meet again, now as adults, to reveal the corruptions in school and to regain one's reputation as a teacher.