Yeon-woo, a noble family member in Joseon, secretly makes clothes and sells them to the market, which is against the code of conduct for noble women in conservative society. One day, she gets in danger of being caught and punished for her clothes being considered too bold and vulgar. Soon, she is almost forced to marry into another noble family without knowing or seeing her future husband. After the wedding ceremony, her husband shares one big secret.

Yeon-woo ends up in Seoul in the present time. She nearly drowns in a swimming pool, but she gets rescued by Tae-ha, who is the grandson of Chairman Kang of SH Group in 2023. Without understanding the current situation, Yeon-woo ends up becoming Tae-ha’s bride. Chairman Kang’s surgery gets delayed, so Tae-ha has to pretend to be married until Chairman Kang leaves for the US. Tae-ha suggests Yeon-woo to draw up a contract regarding their fake marriage.

Yeon-woo believes that she has found a way to go back to Joseon and heads to the pool where she first met Tae-ha in the 21st century. She soon gets caught by Tae-ha and happens to see a piece of painting from Joseon. With her knowledge of the old painting, she helps Tae-ha not to fall for Hye-suk’s scheme which could damage Tae-ha’s career.

Tae-min announces to the whole family that he’ll start working at the company, fighting against Tae-ha to be a successor. He also warns his mother that he hasn’t decided which side to take. Chairman Kang’s birthday is held, and Yeon-woo meets Tae-ha’s whole family, including his aunt. She also runs into Sa-wol, who got hired as the family's new housekeeper.

Hye-suk hands over another business proposal to Midam to make them decline Tae-ha's proposal. Furthermore, she uses Yeon-woo to raise the stakes about Tae-ha's marriage. Meanwhile, Yeon-woo wants to meet Chen-myung again to find the way back to Joseon.

Mi Dam decides to hire Yeon-woo as Midam’s guest designer after seeing her embroidery work. Through this, Yeon-woo gets to participate in SH Seoul’s first-anniversary event, which jars on Hye-suk’s nerves. Hye-suk lures Yeon-woo into the annexe of the family house, knowing Tae-ha hasn’t gotten over his trauma. Tae-ha runs into the annexe to save Yeon-woo, but his heart starts malfunctioning.

The company's biggest event of the year, the first-anniversary event, is just around the corner. However, someone leaks Yeon-woo's collection all over the internet and gets Tae-ha into trouble. Chairman Kang tells Tae-ha and Yeon-woo to give up on the project.

Tae-ha and the whole marketing team go on a vacation to Jeju Island. While Tae-ha is away, Hye-suk holds a general meeting to discuss Tae-ha’s dismissal due to his illness. Yeon-woo confesses her feelings for him, but Tae-ha tells him that they should end everything. Meanwhile, Sa-wol finds out that the Kang Family killed Yeon-woo.

Yeon-woo is devastated upon uncovering that Tae-ha's family from Joseon directly contributed to her demise. Meanwhile, amidst this turmoil, Hye-suk is determined to diminish Tae-ha's sway, but her efforts may have crossed a precarious line.

Ha-na reveals that she had been watching Tae-ha under Chairman Kang’s order. Tae-ha confronts his grandfather and finds out that it was him who killed Tae-ha’s mother. Yeon-woo sees Chairman Kang to ask him to apologize to Tae-ha if he truly loves him. Meanwhile, Mr. Hwang reveals his true identity to Chairman Kang.

Yeon-woo is prepared to go back to the Joseon she came from in order to save Tae-ha. In contrast to Yeon-woo, Tae-ha cannot come to terms with the idea of parting with her, regardless of the circumstances. The farewell is just two weeks away, and Tae-ha values every moment that could potentially be the last memory he shares with Yeon-woo.

Yeon Woo reveals that Lady Yoon tried to throw her into the well and poison her own son to death. Yeon Woo gets attacked by Duk Gu who escaped from the jail. But Yeon Woo thinks on her feet and escapes from his captive. Yeon Woo falls off a cliff while escaping, only to return to the new Joseon.