In the 14th year of Inhwa dynasty, when Emperor Lee Hyeon’s illness gets worse than ever, the empress commands Crown Prince Lee Shin, still in high school, to marry the bride who has been arranged for him beforehand. However, Shin proposes to his secret lover, Min Hyorin, an ambitious ballet student who takes his proposal as a joke and turns him down saying that her success as a ballerina is of her primary concern. Meanwhile, the family of Shin Chaegyeong, an ordinary high school student, is in deep financial trouble for standing security for the wrong person and is overwhelmed with joy when they receive the marriage proposal from the Royal Family. The last words of their dying grandfather weren’t a bluff after all! Shin agrees to marry the all-too-ordinary prearranged bride provided the Changdeok Palace be granted independence and the IkWiSa be reduced.

Chaegyeong, therefore, has no choice but to marry the prince due to her family’s financial crisis. But things aren’t easy, right from the first encounter with the Royal Family. Moreover, seeing that the prince has no affection for her whatsoever, showing careless cynical behavior throughout the wedding process, Chaegyeong comes to regret accepting the proposal. But it’s too late; the Royal Marriage is the top news in the press, and Chaegyeong’s house is crowded with reporters. Prince Lee Yool, the son of Crown Prince Lee Hyoyeol who died in an unfortunate car crash 14 years ago, hurries back to Korea under the urgent order of his mother – Lady Hwayoung, eager to the win back her husband’s throne. In the airport, he runs into Hyorin, who has just returned from her contest, but they don’t recognize each other. Yool has been studying fine arts in England, and transfers to a high school for arts, where Shin and Chaegyeong are also students.

At last, Chaegyeong has made up her mind to join the Royal Family. Lessons for becoming a proper crown princess start as she enters the palace. She has to endure hard training, which includes learning proper ways to talk, memorizing the whole wedding process, etc., with the crown prince showing no interest nor offering any help to her. Life in the palace is not an easy task from day one. A huge ceremony is held to welcome the new crown princess, and with the entire country as witness, Shin and Chaegyeong are wed in the traditional 21st century Royal procedure.

On the first day after the wedding, Shin and the rest of the adults in the Royal Family go out to fight a little war to ensure they receive what was promised to them for granting the marriage. While Shin is being very serious, Chaegyeong, on the other hand, is busy enjoying the privileges of being the crown princess and is slowly adapting to life as a Royal. Chaegyeong and Shin go to school, but Chaegyeong gets treated like an outcast; the only person that actually talks to her is Yool.

Chaegyeong, after making her morning calls to the elders of the royal family, is surprised to see Yool inside the palace. Yool, a transfer student in her class, turns out to be Prince Uiseong. At first, Chaegyeong has a hard time adjusting to life in the palace with its strict education and rules, but thanks to the warmth of the emperor and other elders at the palace she starts to find the royal culture attractive. Meanwhile, Lady Hwayoung prepares to open a yoga center while plotting with Choi against the other royal family members, while Yool gets closer to Chaegyeong and her friends.

Thanks to Yool’s help, Chaegyeong looks good in the eyes of the Empress Dowager Park. In addition, after attending a number of events with Shin, she becomes well known to the public and loved by them for her plain looks and free spirit. Yool tells her she should carry herself with dignity, but she ignores his advice. At the opening of the yoga center, Lady Hwayoung meets Hyorin and finds out that she is the crown prince’s ex-girlfriend, and when Empress Min later finds out Lady Hwayoung has secretly come to Korea and opened a yoga center, she is greatly displeased. Meanwhile, at the palace, a party is held to announce the officially married crown prince and his wife to the ambassadors of the constitutional monarchy.

Kam-ae-tta-la starts to feel uneasy as Chaegyeong adjusts to the palace life. As Hyorin thinks back on the good days with Shin, she remembers what Lady Hwayoung told her and is determined to get Shin back. Meanwhile, Chaegyeong misses her family because she hasn’t seen them since she moved into the palace. But soon, she and the crown prince are finally allowed to go visit her family. Chaegyeong is very happy to be back home, but Shin has a hard time adjusting, due to the fact that he has lived his whole life in the palace. Chaegyeong’s family also feels uncomfortable living in the same house with him. Chaegyeong and Shin, who quarrel frequently, end up spending a night together in Chaegyeong’s small room.

Chaegyeong and Shin return to the palace and after spending time with Chaegyeong’s happy and close-knit family. Shin feels sad to see his family who has always been under the control of his strict father, the emperor. Seeing this, Chaegyeong comforts him, and Shin prepares a car just for her. Persuaded by Hyorin, Chaegyeong and Yool join an equestrian club. Not knowing why Hyorin invited Chaegyeong into the club, Shin’s friends are dissatisfied with the whole idea. Meanwhile, Shin goes to Thailand in place of the emperor, who couldn’t go because of health reasons.

While Shin is away in Thailand, Chaegyeong gets lonely and gets in trouble for breaking the car. After overhearing some girls at school talk bad about her, she gets hurt and asks Yool to just take her away from the palace some place far away from it all. Kang In, Jang Gyeong, Ryu Hwan, and Hyorin all go to Thailand. Hyorin meets up with Shin and asks him to take her to the airport and the two end up spending a day together.

After taking Hyorin to the airport, Shin makes it to the press conference just in time and gives an outstanding speech. Meanwhile, back at the palace, Chaegyeong gets confined to the palace for leaving the palace walls without permission. Yool, after seeing Chaegyeong get in trouble, asks Lady Hwayoung to make him the crown prince. With the help of Yool, Chaegyeong successfully finishes the welcoming ceremony for Prince William, and Lady Hwayoung starts finding back her and her son’s rights as a royal family by asking the emperor to replace back to them Emperor Hyoyeol’s powers.

Chaegyeong insists on riding her horse alone even though the court ladies try everything in their power to dissuade her. While riding her horse she accidentally runs into a stranger in the palace who turns out to be Princess Lee Hyemyeong, Shin’s older sister. Shin is happy to see his sister, whom he hasn’t seen for a long time, and uncharacteristically shows his softer side to her, telling her his deepest thoughts. The paparazzi photos of Hyorin and Shin get reported in the Thai newspapers. Empress Min sees the newspaper and gets angry at Shin. Chaegyeong also finds out about it and gets angry at herself for missing Shin while he was away in Thailand, not knowing that he was with Hyorin. Chaegyeong and Hyorin run into each other at school and Chaegyeong asks her about what really happened in Thailand between the two, but instead of showing a sorry attitude, Hyorin shows a very dignified attitude causing Chaegyeong to faint in front of her friends.

Shin tells Chaegyeong that he is going to withdraw from being Crown Prince, and she starts to feel frustrated because she does not know his true feelings. Chaegyeong tries her best to get closer to him but the more she tries the more frustrated and angrier she gets through finding traces of Hyorin. Eventually she gets into a fight with Shin and breaks into tears. In the palace, the plans for the restoration of Yool’s power are in their final stages and Lady Hwayoung and Yool get ready to move back into the palace. The entrance of a new power figure starts to create a division between people of the court over whom they are going to be loyal to, and Empress Min and Lady Hwayoung are busy keeping each other in check. Empress Dowager Park, who has the final power in deciding whether or not the powers get restored to Lady Hwayoung and Yool, doesn’t know whether giving them the power is the right thing to do or not. Yool and Shin bump into each other in the palace and start a nerve war.

Empress Dowager Park, Shin, and Chaegyeong go on a little road trip around Cheju. Shin and Chaegyeong try everything they can to cheer up the empress dowager. The kids at school start looking at Yool through different eyes when they see his new style. Meanwhile, Empress Min is busy keeping her eyes on Lady Hwayoung, who has moved into the palace. Lady Hwayoung, scolds the crown princess for being lazy and for forgetting about her role and responsibilities as the crown princess. After the pictures of Hyorin and Shin have been revealed to the public, bad rumors of Shin and Chaegyeong start to go around. Worried, the adults of the family gather to discuss a plan to stop them before they get any bigger. They decide to have the couple get into the bridal bed. Having no idea of the plan, Shin drinks some medicine that he was told is good for his body and Chaegyeong gets all dressed up.

After hearing about the couple getting into bed together, Yool runs over to see Chaegyeong. She tells him that nothing happened between her and Shin, and he hugs her, relieved from the unthinkable thought of the two spending the night together. Shin sees this and gets very angry at Yool. Chaegyeong’s friends get angry at Hyorin for starting the rumors and start to criticize her. Chaegyeong learns a secret about Hyorin and starts to feel uncomfortable. Someone leaves a picture inside the crown princess’s room. Chaegyeong is shocked when she sees it and disappears. Shin and Yool soon hear that she has disappeared and instantly go out looking for her.

After finding Chaegyeong in the Myeongsoon Dang, Shin takes her to a place where they can be alone, where they proceed to spill their hearts out and tell their true feelings towards each other. The violence between Yool and Shin becomes known throughout the palace. Lady Hwayoung tells the empress that she is not going to stand by and watch stuff like this happen ever again, raising the conflict between her and the empress. The emperor calls Shin and harshly scolds him, causing Shin to rebel against him. Despite all the malicious gossip about the crown prince and princess, they attend a public conference. When the reporters ask for a loving pose, Shin displays his showmanship. Meanwhile, the empress dowager senses the tense atmosphere of the palace and suggests that the whole royal family should have a meal together.

Shin and Chaegyeong leave on a short honeymoon together. Hyorin leaves on a trip to where she can find traces of Shin and her love. After getting the cold shoulder from Shin, Hyorin remembers what Lady Hwayoung once told her and once again makes a firm determination not to give up. Because of Hyorin, Shin and Chaegyeong feel awkward again and Chaegyeong starts to feel confused when Yool tells her to leave Shin so he can be with Hyorin. The empress finds out about Lady Hwayoung’s plans and starts to take action… Just then the crown prince’s scandal gets known to the public and the palace goes into distress about the matter. The emperor calls Shin and begins seriously considering whether or not Shin is fit for being Crown Prince.

Chaegyeong gets angry at Shin for leaving the palace for a while without telling her where he was going. She asks him why he always keeps everything to himself and worries alone. Hearing this, he suddenly hugs her and asks her to stay by his side even after he resigns from being Crown Prince. Meanwhile, Hyorin, who has come to the palace at the empress’s request, receives an offer from the empress to support her. Yool asks the emperor permission for the crown prince and princess to accompany him on his vacation for his birthday party.

The criticisms of whether the crown prince is good enough or not keep rising; even the emperor starts wondering if Yool is more fit for the spot. Meanwhile, Hyorin discusses with Shin her education plans. Yool tells Chaegyeong, who is feeling miserable at hearing that Hyorin and Shin had once promised to go abroad and study together, how he feels about her.

Chaegyeong gets confused about all the trouble she got into with Shin at Yool’s birthday party. Watching her, Shin feels sorry and apologizes to her, but she doesn’t take his apology and instead their anger toward each other deepens. Chaegyeong hears a rumor about her parents saying that they are profiting with the help of the palace. Hearing this, she starts to feel the palace life more and more stuffy and choking. Shin senses her feelings and lets her get away from everything by having her go home for a night. The empress finds out about it and scolds her for doing whatever she wants to do even though she is the princess. Chaegyeong gets her feeling hurt and runs out of the palace.

Because of an unexpected incident, Chaegyeong ends up in the middle of a rumor. She meets her greatest crisis after becoming Crown Princess and wanting to figure out a way to stop the rumors on her own she refuses help from Shin and Yool. Shin becomes angry at seeing Chaegyeong worrying about how to fix her mistakes and orders the Myeong Seong Dang to be repaired, but this just causes the emperor, Lady Hwayoung, and Yool to get angrier and more frustrated. After seeing Shin isolate himself from the others at the palace, the empress calls him to talk as mother and son. She tells him about what she wishes for him. After seeing Hyorin working towards of becoming her dream to become a ballerina, he thinks again of his dreams and what he really wants. He finds that his future includes Chaegyeong and the empress’s wish and goes to the interview with a firm attitude.

Shin barely manages to cover up for Chaegyeong’s surprise announcement. The adults of the royal family get very angry at Chaegyeong’s actions, which were not in line with the ordinary palace rules. Seeing this, Shin feels sad and angry at the same time. Because of the incident, the scandal of the crown princess blows up again and Lady Hwayoung gets nervous, so she decides to use Chaegyeong as the scapegoat to protect her son. Chaegyeong kneels in front of the emperor to ask for his forgiveness and cries, and Shin just ignores her. Because of the incident, Shin’s ability to be Emperor gets questioned and as this deepens, Yool gains trust from the emperor. In the middle of all this, however, Yool can’t stand looking at Chaegyeong having such a hard time and reveals his feelings in front of all the royal adults.

Yool tries his best to keep faithful to his heart even if it means breaking the rules. Shin insists that rules and regulations are the strength that holds the palace together. Even though their ways of following them and carrying them out are different, the person they want to protect are the same. Chaegyeong also feels bad watching the people she loves and cares for getting hurt, while the reasons and reality also grow farther and farther apart. Meanwhile, the emperor worries about the behavior of Yool and the other royal family members.

Shin gets driven into a corner as an arson suspect. He insists that he is innocent but all the evidence leads back to him. Only Chaegyeong believes him to be innocent and feels bad looking at his drooping shoulders. Shin, knowing that someone actually cares and loves him, doesn’t feel lonely anymore and calmly handles the situation. Yool senses that it was all part of his mother’s plan and tells her to stop whatever she’s planning on doing but she does not know how to stop or even control her ambitions. As more incidents happen the existence of the palace starts to get questioned by the people and in order to stop all the rumors, the emperor suggests that the crown princess should practice more self-discipline.

As the investigation of the arson incident furthers and the facts about it get revealed Shin gets more and more accused of being the cause of it. In the midst of all this, Chaegyeong and Shin’s feelings towards each other grow even stronger and they fight together to get through this storm. The two already resemble each other regardless of Chaegyeong having told him that she has studied hard to be fit for him. The emperor once said that “Apart from the truth of the incident, the person worthy of the imperial throne is the one who receives the love and honor of the people.” Lady Hwayoung smiles a smile of satisfaction and throws in her last card. The empress sees that Chaegyeong has slowly started to show the qualities of a crown princess and for the first time, they actually sit down and talk with each other. The empress encourages her and gives her strength.