Right when Yerim refuses to go along with Soo Ji's idea because she doesn’t feel like being threatened, both of them receive a message from Seung Yi on the group chat, asking Soo Ji to stop what she’s doing; otherwise, she will harm herself. Shocked, they rush back to Class 5 with all the other girls, trying to get in and stop Seung Yi from hurting herself. But before they can get in, Seung Yi cuts her wrist, and some blood drips onto the floor. Harim steps up and takes the knife from Seung Yi's hand. Soo Ji arrives, and everyone stares at her. Harim confronts Soo Ji, asking why she would do something like that to Seung Yi. Soo Ji realizes she has fallen into Harim's trap, framed as the villain. Everyone starts shouting at her, blaming her for making Seung Yi attempt to take her own life. At the same time, Ms. Yoon informs Soo Ji's father, Lieutenant Jung, about the bullying in Class 5, telling that his daughter might be one of the victims. Ms. Yoon wants him to see for himself and leads the parents back to the class. Everyone arrives right at the moment when all the students are blaming Soo Ji for what Seung Yi has done. People start calling Soo Ji the bully, while Harim steps up again, acting like a savior, and says that Soo Ji is just new to the class and needs some time to adapt. Harim's mom, the school director Choi Yi-hwa, also says that the kids have their own system for dealing with things like these and asks the parents to stay out of it. So later, the parents stay outside and look into the class when Soo Ji stands in front of the class, waiting for her classmates to discuss her punishment for breaking the rule: bullying a Rank D student as a Rank C student. Da Yeon wants all of Soo Ji's votes to be confiscated. Seeing that all her plans will be ruined if this happens, Soo Ji asks Seung Yi to show the proof that Soo Ji bullied her, but she doesn’t have any. Harin says they should decide Soo Ji's fate by voting. Everyone outside seems satisfied and says it's democratic to do it this way, but Ms. Yoon thinks it’s actually a public execution. Ms. Yoon wants to intervene, but Harim's mom stops her and whispers that she will make Soo Ji's life miserable if she does so. Inside the class, 21 people vote for Soo Ji not being able to vote tomorrow, and Soo Ji realizes she’s doomed. Soo Ji and her group go to the rooftop. Hae Jun texts her that she won't vote for Soo Ji anymore and if Soo Ji keeps threatening her, she will do the same thing that Seung Yi did. Soo Ji realizes Ja Eun was right about choosing to make friends instead of blackmailing their way out because Jae Hyeong still stays with them. Soo Ji doesn't understand why Harim knows so well about her plan. When they come back to the class, Harim is doing a presentation about the pyramid game and asks the parents to participate, but her mom stops her. However, her grandmother shows up and allows her to continue the game. Everyone does the voting except for Soo Ji's dad, and the result is that Soo Ji has 0 votes and is ranked F.

Harin asks Soo Ji's dad what he feels about that, and he says that school is just like a miniature of real life and hierarchies exist everywhere and it’s common. Soo Ji is infuriated by his answer and questions if he knows what Rank F students have to go through, even wanting to kill themselves, and states that Soo Ji will break this stupid pyramid game. Somehow, Harin's grandmother is impressed by Soo Ji's spirit and goes to shake hands with Soo Ji's dad, and Eun Byeol takes a photo.

After everyone leaves school, Soo Ji finds a hidden camera on top of the board and thinks it was placed there by Seung Hwa. At night, Harim texts someone and tells them that she will make Ja Eun be Rank F tomorrow. The next day, Yerim comes up to Harim and tells her that involving the parents in the game yesterday was breaking the rules. Yesterday, she and Soo Ji discussed, and Soo Ji tells her she would never use her relationship with Eun Jeong against her, so Yerim agrees to help Soo Ji take over the game. Harim asks the other girls if they think this way and uses her power with some threats from Da Yeon and Woo Yi to back her up. Of course no one would dare to say anything and Yerim proposes they should vote anonymously. There are 13 votes against Harin, and she too has her voting rights taken away. It turns out Soo Ji's plan was to push Yerim to be the Rank A student this time. Soo Ji asks Ja Eun to vote for Ye Rim and not to vote for her because she wants to be Rank F again and can get more proof of bullying with the hidden camera. However, during P.E., Harin is alone in class and finds the hidden camera. Later, Yerim's friend shows her an online article exposing how her dad bribed her way to fame and to debut as an idol. Eun Jeong is angry and wants to find out who did this. It turns out that the person who wrote the article is Woo Ri, who somehow has an extreme obsession with Yerim. In the class, one girl mocks Yerim and makes Eun Jeong suspicious, so she stands up and slaps that girl. The girl fights back, so she continues hitting her until Ja Eun intervenes. At that moment, Harim looks at the picture online and says that the photo looks like it was taken from a hidden camera from an above angle. So, Eun Jeong goes around the class looking for it and finally finds the camera Seung Hwa has placed. Soo Ji knows this was Harim's plan to destroy the hidden camera, and the one who took the picture of Yerim is no one else but Seung Yi, who also has an anti-page of Yerim on Instagram. Eun Jeong finally finds the camera and wants to know to whom it belongs. Yerim is angry because Eun Jeong not only messed up her and Soo Ji's plan but also caused some of their classmates to bleed out. She asks Eun Jeong to apologize, but Harim interrupts and tells Eun Jeong that they should get the memory card to find out who placed it there. At that moment, Ms. Yoon comes in and claims that the camera belongs to her. Before Harim can question her further, Ms. Yoon smashes the camera under her shoe in front of everyone. After that, Ms. Yoon resigns from her job. Before leaving, she gives Soo Ji her contact number and asks her to win. A flashback shows that she had proof of school bullying in class 5 and showed it to the principal, but she was insulted and dismissed by the principal right away. After that, she was also called into the director's office and got threatened by Harim. After that, Soo Ji calls Ja Eun and Ji Ae to meet on the rooftop. Soo Ji reveals that ji ae was the person who informed Harim about the camera. She and Seung Yi were the informants of Soo Ji's plan to Harim all along. Ja Eun is sad because she was the person who told Ji Ae about the camera last night, and Soo Ji asks her to leave. With the camera taken away, Soo Ji says they have to proceed with a Plan B. After that, they return to the class and start the monthly voting; this time, both Soo Ji and Ja Eun get Rank D, and no one gets Rank F. Yerim gets Rank A as planned, and Ji Ae gets Rank D. The most surprising is that the class outcast, Eun Byeol, gets Rank A. Do Ah, Da Yeon, and Woo Yi are shocked that they dropped in rank. Harim is still Rank A but is still mad that Ja Eun isn't Rank F as she wanted. After the votes, Seung Hwa hacks into the system and sends Soo Ji the names of the people who voted for her and Ja Eun. Yerim was the one who voted for both of them, besides Jae Hyeong.