1. Sezon

Soo Ji transfers to Baekyeon Girls’ High School and discovers that her class plays a game called the Pyramid Game in which the students decide on a hierarchy based on a popular vote. As Soo Ji ends up in the lowest rank, she devises a plan to get back on her feet.

Soo Ji is determined to figure out the characteristics of her classmates and the mastermind behind the Pyramid Game. She also tries to join forces with other girls who seem vulnerable. She even asks her homeroom teacher for help, only to be disappointed. Meanwhile, the 14th Pyramid Game begins, and Ja Eun, who kept skipping school, shows up.

Soo Ji moves up to Grade C, and the treatment she gets changed completely overnight. She breaks the promise she made with Ja Eun, but she decides to join hands with her and help the new girl in Grade F, Pyo Ji Ae. Soo Ji, Ja Eun, and Ji Ae come up with a plan to destroy the pyramid altogether.

Soo Ji begins to feel uneasy about the unfolding events, suspecting that her plan may have been compromised and that Ha Rin is catching on. Learning this, Pyo Ji Ae worries she may have made a mistake and dreads the potential consequences. Meanwhile, Soo Ji hints to Hae Jun that she holds leverage over her, coercing Hae Jun into assisting her. Soo Ji recruits a hacker to join her team.

Veli ziyareti sırasında, Soo Ji, Ha Rin’in tuzağına yakalanır. Soo Ji, Do Ah ile anlaşmaya çalışırken Seung Yi, Soo Ji’yi zor durumda bırakmak için bir gösteri yapar. Veliler olaya tanık olsa da Ha Rin durumu lehine çevirir ve hatta Baekyeon Grubu’nun başkanı olan büyükannesini de işin içine katar. Bu sırada Soo Ji B planına geçer.

15. oyunda F notu olmayan Soo Ji, Ye Lim'ın yardımıyla oyunu eleme vitesini değiştirir. İlk olarak, A sınıfı ayrıcalıklarını iptal etme teklifi getirir ve Ha Rin'i zor durumda bırakır. Bu sırada Ha Rin, Soo Ji'nin engellemelerine boyun eğmez ve Soo Ji'nin oyununu yıkmak için bir plan düşünür.

Baekyeon Girls’ High School goes on a school retreat. While practicing diving, someone pushes Ha Rin into the water, and Ja Yeon jumps in to save her. The next day, Class Five plays a survival game using paint guns. The last five standing, Soo Ji, Ja Eun, Jae Hyung, Eun Jung, and Ji Ae are put in danger of ending up in Grade F.

Soo Ji decides to recruit more girls to end the game and Ha Rin for good. When Da Yeon is about to be punished for what she did to Eun Jung, their teacher tells everyone that Da Yeon has to transfer to another school. Meanwhile, right before the Pyramid Game is held, Ye Lim gets taken to the hospital.

16. Piramit Oyunu başlar ve Ha Rin, kalıcı F Sınıfı olacak bir sınıf arkadaşı seçilmesini önerir. Oylamadan önce Soo Ji, Ye Lim'ın saldırıya uğradığını ve hastaneye kaldırıldığını sınıfa söyler. Sınıf, oyuna devam edip etmeme konusunda oylama yapmaya karar verir ve tüm süreç canlı yayınlanır, bu da okulun karışmasına neden olur. Bu sırada Ja Eun, Soo Ji'ye küçükken Ha Rin'e yaptıklarını anlatır.

Ja Eun reveals what she used to do to Ha Rin, but Soo Ji thinks Ha Rin is just using it as an excuse to make Ja Eun's life miserable. The school and Baekyeon Group decide to blame Soo Ji and her group for the violence at school, but Ms. Yoon Na Hee takes action and reveals the video of Soo Ji being bullied. Meanwhile, Soo Ji reveals the corruption behind the teacher recruitment.