After Oh Si Eun's death, Kim Hye In becomes the prime suspect in the murder investigation. At school, her classmates harass her with scorn, labeling her an 'Equal Opportunity loser.' Realizing that she may never be able to change the course of her life, Hye In resolves to fight back.

Je Na goes through daily distress caused by her family. Her father is on the verge of divorce, and Cha Jin Uk, a suitor with a contract marriage in mind, suddenly enters the picture. Meanwhile, facing expulsion, Hye In proposes a deal to Je Na to include her as a member of Diamond 6. Would Je Na accept Hye In’s offer?

With Je Na’s help, Hye In makes it into Diamond 6 and decides to act accordingly. Meanwhile, Hae In regains consciousness in the hospital and returns to Cheongdam International High School, but she appears to have lost her memory. Another new student, Jin Uk becomes the subject of gossip. As the backstories of the main characters gradually come to light, will Hye In be able to make it through school life safely?

Amidst being mistreated and looked down upon for her memory loss, Hae In seems to make up her mind and asks Do Eon to take her as his partner to the party. Meanwhile, Je Na joins the party and reveals her secret in front of everyone. As the main characters make bold moves, what is the secret that Hae In is hiding? And what kind of consequences will it bring?

As relationships twist and allegiances shift, Yul Hui begins reaching out to Je Na’s enemies, determined to bring her down. On Je Na’s side, her once dismissive attitude toward Jin Uk begins to soften and the two form a reluctant yet increasingly cooperative alliance. In a tangled web of betrayal, manipulation, and shifting loyalties, no one can tell who is truly a friend or an enemy.

Hye In interrogates Sa Rang about whether he is actually Black Dog. Ultimately, Sa Rang confesses the truth regarding Oh Si Eun’s cellphone. After hearing Sa Rang’s account, Hye In is convinced that the person who took Si Eun’s phone is the one who pushed Si Eun. Meanwhile, rumours begin to spread about Baek Je Na’s drug abuse.

Framed in a drug scandal orchestrated by Yul Hui, Je Na’s downfall seems imminent, until her allies step in. Meanwhile, Hye In follows a clue tied to a wrist injury and begins to suspect who holds Si Eun’s phone. With everyone hiding their true loyalties and intentions, can Hye In uncover the truth and protect herself before it’s too late?

Tensions escalate as Hye In is forced into submission, becoming Yul Hui's pawn. However, Yul Hui's schemes unravel when her role in a setup against Je Na is exposed, putting her in a desperate position. Meanwhile, a new strategy emerges to take down Diamond 6 members, with plans to leak the truth through Black Dog's channel.

After Hae In's death, the fragile balance between the characters starts to collapse. Yul Hui pressures Hye In to expose Je Na with a lie during her engagement ceremony with Jin Uk, using a video as leverage. As the fateful day approaches, Hye In stands at a crossroads. With everyone watching, Hye In’s next move could change everything. Will she betray and bring Je Na down, or choose the truth?

Despite the risk of revealing herself, Hye In bravely exposes Yul Hui and the web of corruption festering within the school during Je Na's wedding. As her meticulous plan sets off a chain reaction, buried truths begin to surface, drawing everyone deeper into chaos. Loyalties get tested, and tension simmers dangerously close to exploding. Meanwhile, Yul Hui seethes with rage as damning accusations come at her from all sides.