Meanwhile, in Myungsung High School, when Ah-ran befriends the class outcast Jin Yi–kyung, it makes her the target of the school bullies who make her life hell, yet she's too proud to tell her mother what's happening. When Kang-ja finds out that her daughter is getting bullied, she decides to take matters into her own hands. Unbeknownst to Ah-ran, Kang-ja enrolls in Myungsung High as an undercover student with the false name "Jo Bang-wool" to teach those bullies a lesson. But she ends up unraveling the darker problems within the educational system. Kang-ja makes it her mission to put a stop to the school violence, dig up the flaws of the education system, and school corruption at Myungsung High with the help of Ah-ran and naive, idealistic homeroom teacher Park No-ah.
