A new year starts for Liyan Kindergarten, the global leader in the field of early education. Parents from prestigious backgrounds gather for a fundraiser at Liyan. Kang Youn-kyum, the representative of LY Group, also attends with his wife for her daughter. However, there he meets a young woman who sparks something in his heart. A spark that can endanger everything he built until now.

While satisfying Dam-ri and Ji-hee, Sun-bin approaches So-ra at the same time. With her charms and wit, she manages to obtain So-ra’s trust. Sun-bin and Jin-wook get invited to Sewoonjung, Youn-kyum’s personal party where not anyone can join. By using this big step, Sun-bin moves forward with her plan of vengeance for her true identity, Ra-el.

Sun-bin is on a clear path to gaining So-ra’s total trust. With the trust she gains, she must investigate the ledgers of LY Group that might be in Youn-kyum’s study. However, Eun-pyeong finds shocking information about Kang Youn-kyum. Something that Ra-el has no clue about and something that can ruin her plan of taking down LY Group.

Youn-kyum does not fall for Ra-el easily. Just when things seem to be in a tight spot, Ra-el comes up with a plan by using So-ra’s birthday. Meanwhile, although Eun-pyeong is well-known for not taking any politician or conglomerate’s side, he is willing to do whatever he can to help Ra-el achieve her goal. Step by step, she becomes closer to punishing all those who destroyed her family.

So-ra is enraged with Youn-kyum’s disappearance. Despite the presence of her daughter, she does not control her emotions. Meanwhile, Youn-kyum confesses his true feelings to Ra-el. With true love as his source of energy, he determines to break free from being LY’s puppet. Ra-el’s revenge begins to speed up. The day of vengeance is soon to come.

Now that Ra-el knows about her mother Jin-sook's death, she seeks revenge by getting close to Youn-kyum. Ra-el sees his scars. She knows it isn't right, but she can't resist and slowly falls for Youn-kyum. Eun-pyeong teams up with Pan-ro to help Ra-el. Meanwhile, So-ra's compulsive behavior goes out of control when she suspects Youn-kyum is seeing another woman.

So-ra uses the hit-and-run accident to her advantage and begins to search for Youn-kyum's mistress. Ra-el keeps her distance, hitting Youn-kyum and So-ra mentally. And as soon as she disappears, Youn-kyum yearns for her even more. Meanwhile, So-ra kidnaps Ra-el's bodyguard to find Youn-kyum's woman, and a fierce battle of nerves begins between So-ra and Ra-el. Later, Ra-el makes her return dressed lavishly.

Youn-kyum and So-ra don't react as Ra-el expected. So-ra starts to ostracize Ra-el at the kindergarten now that she knows Ra-el is Youn-kyum's mistress. Ra-el starts to become anxious, seeing no difference in Youn-kyum and So-ra's relationship. Meanwhile, Eun-pyeong takes the president's chief secretary position and vows to help Ra-el get her revenge as his love for her grows deeper.

Ra-el falls deeper into the darkness after Moon-hee's betrayal and Youn-kyum's indifference. To get Youn-kyum to move, Ra-el deals with him coldly, grabbing and letting go of his heart. Later, at LY Shopping Mall's formal gathering, So-ra falls into Ra-el's plot.

Youn-kyum goes to the house of roses after he tells So-ra he wants a divorce. His love deepens while enjoying his time there. He tells Ra-el he loves her. She tries to turn a blind eye to his endearment, but she can't help herself and falls deeper into love. Meanwhile, Eun-pyeong warns Ra-el that it could get dangerous if she stays with Youn-kyum.

Ra-el sees Youn-kyum's sincerity and gets torn by her love for him and her revenge. Meanwhile, news about Youn-kyum's private life begins to circulate that enrages So-ra. So-ra orders one of her men to capture Ra-el at all costs. Eun-pyeong saves her but sustains a critical injury. And because of it, Ra-el determines to face So-ra head-on and take what's hers.

So-ra gives Youn-kyum clues about Ra-el's identity. Ra-el and Youn-kyum's relationship becomes compromised with So-ra's drop of doubt. Realizing there isn't much time left, Ra-el thinks only of her revenge. Youn-kyum senses Ra-el's secret, but it doesn't cloud his love for her. And Ra-el has a hard time taming her heart for his unconditional love.

Youn-kyum is utterly shocked when he learns about Ra-el's secrets. Ra-el and Eun-pyeong believe Pan-ro has Moon-hee. Eun-pyeong storms Pan-ro's residence with the police to search for Moon-hee, but they come up empty-handed. Ra-el learns more about her mother's death and becomes further enraged. Ra-el takes the lead in Moon-hee's place to finish her revenge, and Eun-pyeong helps her in any way he can.

The trial proceeds as scheduled, and Youn-kyum himself shows up in the courtroom. At the same time, with the evidence left behind by Moon-hee, Ra-el turns So-ra and Pan-ro against each other. Cornered and pressured, So-ra finds herself turning into the weakest version of herself. Meanwhile, Youn-kyum asks for forgiveness, even if it means sacrificing his own life.

Jung-chul heads to the villa where Ra-el and Youn-kyum are. He is determined to hurt Ra-el as much as she had hurt him. Youn-kyum ends up killing Jung-chul, and he decides to turn himself in. Ra-el receives the gift Youn-kyum left him, and she decides to leave for Buenos Aires upon seeing it. Sometime later, Eun-pyeong decides to go and see Ra-el in Buenos Aires.