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.
EPISODE 1
Episode 1
Ji Yoon-soo, math teacher, set to marry, assigned to prestigious Asung High School in Gangnam.
EPISODE 2
Episode 2
Yoon-Soo realizes that Seung-Yu is the one who guessed the math club's Calculus question.
EPISODE 3
Episode 3
When Yerin learns that Seung-yu used to be a math prodigy, she feels uneasy.
EPISODE 4
Episode 4
Seung-Yu and Yerin start preparing for the Math Olympics in earnest.
EPISODE 5
Episode 5
Seung-Yu opens up to Yoon-Soo about a past trauma she hasn't been able to tell anyone about.
EPISODE 6
Episode 6
Yoon-soo has mixed feelings about Seung-yoo's confession.
Im Soo-jung
Lee Dohyun
Jin Kyeong
Choi Dae-hoon
Oh Gwang-rok
Jeon Guk-hyang
Moon Seokhwan
Oh Kwanghee
Kim Ji-un