Cinderella at 2AM

After dating Ju Won for a year and a half without knowing he was the youngest son of the AL Group family, Yoon Seo decides to break up with him at his mother's request while accepting her money. As promised, she attempts to break up with him by making him gradually resent her.

Now, as the AL CARD's director and Yoon Seo's superior, Ju Won declares war against Yoon Seo in an office he picked right next to hers. He vows he will never let her go and turns up his charms. Meanwhile, Yoon Seo succumbs to his request to eat with him 27 times.

Ju Won and Yoon Seo wake up in despair after realizing what they did and said to each other last night, intoxicated. They try to avoid one another at the company. Meanwhile, Ju Won's mother reminds Yoon Seo of her promise, and Yoon Seo's brother gets in trouble at school for school bullying.

An unknown number keeps texting Yoon Seo's phone with messages only an ex-boyfriend would text, making her suspect Ju Won. She confronts him about it. Meanwhile, the company's new venture in the vacation sector opens a hanok getaway where Yoon Seo's team and Ju Won go for a business trip.

Joo Won leaves his family and shows up at Yoon Seo's door. His appearance exposes their relationship to the team, who even discover that their breakup was because of Joo Won's family's opposition, causing them to create an unbearable atmosphere for her in the office.

Yoon Seo struggles to clarify her relationship with Joo Won, even though she knows it's over. On top of that, Sung Min unexpectedly enters her life, sparking Joo Won’s jealousy. Feeling overwhelmed, she lashes out at Sung Min’s frivolous words and actions.

While Yoon Seo and Sung Min seem to be getting closer, Ju Won becomes jealous and resorts to Si Won's advice of turning on his belligerent side. His sudden demeanor confuses her and frustrates her, angering her. But when she sees Ju Won with another woman, she is shocked by how flustered it made her

Joo Won shows up at Yoon Seo's mother's funeral, and she cries in his solace. Then, he surprises her with a marriage proposal, leaving her speechless. As he waits anxiously for her answer, he has to go to Spain, but Yoon Seo rushes to see him at the airport as if she will lose him forever

Yoon Seo realizes that before she can be honest about her relationship with Joo Won, there's something she needs to address first. Meanwhile, Si Won and Mi Jin are enjoying a wonderful night out together, but what starts as a moment of sincere honesty unexpectedly turns awkward.

While Joo Won and Yoon Seo enjoy the outdoors, the shocking news of Seon Joo's husband's affair in New York spreads. To remedy the shattered image of the company, Seon Joo allows Yoon Seo to marry Joo Won.