New student Seong Su-ji is introduced to a ranking system called the Pyramid Game that chooses class outcasts via secret vote. Su-ji must decide whether to accept her status, or partner with a fellow outcast to topple the Pyramid Game.

Su-ji becomes the target of vicious bullying when she discovers a popular classmate is related to the inventor of the Pyramid Game. A teacher offers to help Su-ji, while a blackmail scheme is revealed. Su-ji shares a resolution with Ja-eun.

After the latest Pyramid Game vote, Su-ji and Ja-eun improve their class rankings. Ja-eun tries to protect the newest outcast, while Su-ji feels it's not her business to intervene. Su-ji finds out she had help behind the scenes.