Set at Baekyeon Girls' High School, the series follows Sung Su-ji, a new transfer student who quickly discovers a brutal social hierarchy known as the 'Pyramid Game.' Once a month, students participate in a secret vote that ranks their popularity and social standing. Those who receive an 'F' grade become the target of legalized school violence, suffering systematic bullying from their peers. Determined to dismantle the corrupt system, Su-ji transforms from a target into a strategist. She joins forces with other students to expose the cruelty of the game and bring down the ringleader, Baek Ha-rin, who sits at the top of the pyramid. The series explores themes of power dynamics, the psychological toll of bullying, and the struggle for justice within an oppressive environment.