I Don't Want to Be Friends with You Episode 4

Li Jin Bu and Chen Jun He's argument leads to a fight in the classroom. Both of them are reprimanded by the Discipline Director and asked to submit self-criticism. Jun He demands an apology from Jin Bu, which she refuses to do. Both Li Jin Bu and her friends are bullied as a result. Their grudge escalates further as they pull petty pranks on each other. Qing Tong asks for an apology in Jin Bu's stead, but Chen Jun He doesn't accept it. Both of their parents called the school,l and Li Qing Tong's mother is angered by the kids' behavior. At school, as Jin Bu is still adamant about refusing to apologize, Li Qing Tong goes up to Chen Jun He and slaps herself on the face with his shoe as repayment for what Jin Bu had done to him. (Source: iamconqueror at MyDramaList)