Drama series follows the turbulent life of Jang Ok-Jung (Kim Tae-Hee), who is also known as Lady Jang Hui-Bin, one of the most famous royal concubines in the Joseon Dynasty. She began her career as a court lady who stitched clothing as a fashion designer of her time.

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Jang Ok-Jung's mother was a slave, but her father was a middle-class merchant seller. When she was a teen, her whole family went on the run from slave hunters. Her older brother was lost during this time. Her father was also beaten to death and Jang Ok-Jung's mother was returned to her owner. Afterwards, Jang Ok-Jung lived with a friend of the family, Madame Jung Kang (Yun Yu-Seon). During this time she learned how to sew at Madame Jung Kang's linen shop. She also met for the first time Crown Prince Lee Soon (later played by Yoo Ah-In) around this time. Crown Prince Lee Soon spotted pickpockets stealing from Jang Ok-Jung and came to her aid. They spent a moment together while taking shelter from the rain. Crown Prince Lee Soon fell in love with Jang Ok-Jung then. Even though Lee Soon was the Crown Prince, he was basically powerless at the time. Power was actually wielded by the noblemen. This drove Lee Soon to become a powerful king one day.

As an adult, Jang Ok-Jung runs her own clothing boutique named "Booyongjung". Her handmade clothes become quite popular and in demand. Jang Ok-Jung hopes to free her mother from slavery with her earnings and eventually go to Qing with her.

Jang Ok-Jung then puts on a fashion show. Her mother's owner attends the fashion show and ruins everything for Jang Ok-Jung. She berates Jang Ok-Jung in front of all of her clients, informing everyone her mother is a slave. After the show, Jang Ok-Jung's business quickly goes downhill. A customer then requests Jang Ok-Jung to make clothes for a royal family member, which she promises to do.

Meanwhile, Crown Prince Lee Soon struggles to gain power from the nobility. He only trusts Prince Dongpyung (Lee Sang-Yeob). Lee Soon is now of age to marry. His mother and the man he despises the most, Nobleman Min Yoo-Joong (Lee Hyo-Jeong), decide that Lee Soon will marry nobleman Min Yoo-Joong's daughter Inhyun (Hong Soo-Hyun). Inhyun has been raised to become a queen from a young age and she has never once doubted her fate. Lee Soon's mother and Nobleman Min Yoo-Joong are nervous though that Lee Soon may reject Inhyun due to her father. Because of this, Crown Prince Lee Soon's mother and Nobleman Min Yoo-Joong concoct a plan.

Crown Prince Lee Soon then sees a woman in the garden. That woman is Jang Ok-Jung, who is waiting to take his measurements. Crown Prince Lee Soon thinks she looks familiar, but he can't place where they have met before. The Crown Prince then asks Jang Ok-Jung if they have met before, but she says no.

Jang Ok-Jung later goes to her mother's owner to buy her freedom, but the slave owner refuses. Jang Ok-Jung asks the slave owner for a reason why her offer is refused and the slave owner tells her to go ask her uncle Jang Hyun (Sung Dong-Il). Her uncle is a highly ambitious man, who hopes to use Jang Ok-Jung for his own ambitions.

Meanwhile, Prince Dongpyung, the man Crown Prince Lee Soon trusts the most, takes an interest in Jang Ok-Jung. Prince Dongpyung then arranges a party where he can spend more time with her. At the party, Crown Prince Lee Soon is also there.