The once-unshakable hierarchy at Cheongdam International High School is now shattered!br Kim Hye-in, a witness to the two murders of the first members of the Diamond 6 from the underprivileged class. Baek Je-na, a queen whose world is threatened by the collapse of the succession structure, strained friendships, and suspicions against her as the murderer. Kim Hae-in, a returning Cinderella who dreams of revenge but not love. Seo Do-eon, who is in a state of confusion after facing the tragic truth of what she believed to be love. Min Yul-hee, who chooses to embrace complete unhappiness if happiness cannot be achieved. Park Woo-jin, full of selfishness and an inferiority complex. And Lee So-Mang, an unpredictable mastermind.