Inhwa, Year 14, when King Hyun’s (Park Chanhwan) illness worsens, the Queen Dowager (Kim Hyeja) orders Crown Prince Shin (Ju Jihun) to submit to an arranged marriage. Shin (Ju Jihun) proposes to dance major Min Hyorin (Song Jihyo), who he’s secretly dating, but she thinks he’s joking and refuses him, saying that her dream of becoming a successful ballerina is more important to her.
Meanwhile, Chaegyeong (Yun Eunhye) is an ordinary high school student whose family is in deep financial trouble because her father had been guarantor to a person who skipped town without repaying the loan he’d taken out. When the Royal Family notifies her of the arranged marriage, it throws her world upside-down. What the family had thought was a joke in Grandpa’s will was for real.
Shin has already accepted that as Crown Prince, his life is not his own. He agrees to marry ordinary high school student Chaegyeong in exchange for permission to live in Changdeok Palace and the reduction of the number of bodyguards he must have with him.
Chaegyeong happened to witness Shin’s proposal, and argues that an arranged marriage is ridiculous and illogical. Just then, debt collectors charge into her family’s house and start putting red stickers on everything…
Chaegyeong (Yun Eunhye) eventually agrees to the marriage because of the state of things at home. However, from the first meeting with the Royal Family, communicating proves difficult. In addition, Shin (Ju Jihun) couldn’t care less about Chaegyeong and is cynical about the marriage, making Chaegyeong regret her decision. It is too late though, as the news has already been publicly announced, and Chaegyeong’s family becomes the center of negative media attention.
Meanwhile, Yul (Kim Jeonghun), the son of Crown Prince Su who died 14 years ago in a car accident, follows his mother Hwayeong’s (Shim Hyejin) orders and returns to Korea. Hwayeong wants to reclaim the throne. At the airport, Yul runs into Hyorin (Song Jihyo), who is leaving to participate in a competition, but neither recognize each other. Yul, who studied art in England, transfers to the art high school that Chaegyeong and Shin are attending. Shin is happy to see Yul and greets him as a friend, but the Queen (Yun Yuseon) is worried…
Chaegyeong (Yun Eunhye) is finally determined to be Crown Princess.
As soon as she moves into the palace, her training begins. Learning the palace speech is a given, and it is difficult for her to learn the proper order and etiquette for the upcoming ceremonies, but her fiancé Shin (Ju Jihun) doesn’t so much ignore Chaegyeong, as he is cold to her. Chaegyeong’s palace life is rough and difficult from the start.
The ceremony installing the Crown Princess takes place. Shin and Chaegyeong’s traditional marriage takes place in the 21st century as the entire Royal Family and all the citizens look on. Meanwhile, Hyorin (Song Jihyo), who rejected Shin’s proposal, is on stage in Thailand at the ballet competition…
On the first night following the wedding ceremony, Shin (Ju Jihun), butts heads with the adults. It is over the conditions that he agreed to the marriage on. Unlike serious Shin, Chaegyeong (Yun Eunhye) begins to feel better about being Crown Princess as she slowly adjusts to life in the palace.
Shin and Chaegyeong return to school after a long absence. Chaegyeong, who is a real-live Cinderella, becomes an outcast at school. The only person who will talk to her is sweet transfer student Yul (Kim Jeonghun). Shin runs into Hyorin (Song Jihyo), who has just returned from the ballet competition…
Early in the morning, Chaegyeong (Yun Eunhye) is surprised to see Yul (Kim Jeonghun) in the palace on her way back from saying good morning to the adults. Classmate and transfer student Yul’s true identity is Prince Uiseong. Chaegyeong is having a hard time with the strict training, but through the King and the other adult’s warm concern, begins to appreciate the positive aspects of palace culture.
Meanwhile Hwayeong (Shim Hyejin) opens a yoga center as a front and starts scheming with Editor Choe, preparing for her return to the palace. Yul gets closer to Chaegyeong and her friends.
It is almost Crown Prince Shin’s (Ju Jihun) birthday. Chaegyeong is excited about the party at the Royal Family’s resort but among the guests are Shin’s friends, who think very little of her, and Hyorin (Song Jihyo)…
Chaegyeong (Yun Eunhye) earns brownie points with the Queen Dowager (Kim Hyeja) with Yul’s (Kim Jeonghun) help. The Crown Prince and Princess begin making public appearances and Chaegyeong’s free and ordinary image is warmly welcomed by the people. Shin (Ju Jihun) admonishes Chaegyeong to stop behaving like such a commoner but she doesn’t listen.
Hwayeong (Shim Hyejin), after overhearing that Hyorin (Song Jihyo), who she met at the opening of the yoga center is Shin’s ex-girlfriend, gets friendly with her while the Queen (Yun Yuseon) gets anxious after hearing the belated news that Hwayeong returned secretly and opened a yoga center.
Meanwhile, a party formally introducing the Crown Prince and Princess to ambassadors from other countries ruled by monarchies is taking place at the palace…
Chaegyeong (Yun Eunhye) continues adapting to being Crown Princess, and Hyorin (Song Jihyo) starts feeling uncomfortable. Going off of Hwayeong’s (Shim Hyejin) suggestion, Hyorin, who had been reminiscing about her memories with Shin, determines that she will win him back.
Meanwhile, Chaegyeong hasn’t returned home once since she came to the palace and really misses them. After receiving permission from the adults, the Crown Prince and Princess finally set off to visit her home. Chaegyeong is in high spirits, but Shin has a difficult time adjusting to an atmosphere completely unlike what he’s used to at the palace. Chaegyeong’s family also isn’t sure how to act with their new royal family member. Constantly quarreling Shin and Chaegyeong end up having to spend the night together in Chaegyeong’s tiny room…
The Crown Prince and Princess return from their visit with the in-laws. Shin (Ju Jihun) feels hurt because the Queen (Yun Yuseon) is always strict and severe, unlike Chaegyeong’s (Yun Eunhye) family members, who are warm and friendly. Chaegyeong comforts Shin. Shin obtains a car for Chaegyeong’s personal use.
Hyorin (Song Jihyo) get Chaegyeong and Yul (Kim Jeonghun) to join the equestrian club. Shin’s friends don’t know what Hyorin is up to but aren’t happy with Chaegyeong joining the club.
Meanwhile, Shin, in the ill King’s (Park Chanhwan) stead, visits Thailand by himself…
While Shin (Ju Jihun) is in Thailand, Chaegyeong (Yun Eunhye) wrecks the car and is reprimanded. Lonely and hurt by criticism from her classmates, she asks Yul (Kim Jeonghun) to take her anyplace that isn’t the palace.
Hyorin (Song Jihyo) goes to Thailand with In, Gyeong, and Hwan. She meets Shin and asks him to take her to the airport, leading him on a date.
Meanwhile, the palace is in an uproar because Chaegyeong has gone missing…
Shin (Ju Jihun) just barely makes it back in time to give a well-received speech after taking Hyorin (Song Jihyo) to the airport.
Meanwhile, Chaegyeong (Yun Eunhye) is punished for going off palace grounds without permission. Seeing this, Yul (Kim Jeonghun) asks Hwayeong (Shim Hyejin) to make him king. Chaegyeong successfully escorts Prince William throughout his visit to Korea with Yul’s help and Hwayeong begins laying the foundation for her plans by asking the King (Park Chanhwan) to bestow the title of King to late Crown Prince Su.
Chaegyeong (Yun Eunhye) pays no heed to attempts to stop her and tries to practice riding by herself. While racing with the horse, she runs into a stranger. The stranger is none other than Shin’s older sister, Princess Hyemyeong (Lee Yunjin). Shin (Ju Jihun) welcomes his sister, who he hasn’t seen in a long time. Unlike his usual self, he shows a sweet side and talks about his thoughts and feelings with his sister.
The Queen (Yun Yuseon) is upset when she learns of the paparazzi pictures of Shin and Hyorin (Song Jihyo) that have been published in Thai newspapers. When Chaegyeong learns of this, she becomes upset and thinks she’s a fool for having missed Shin while he was in Thailand. Chaegyeong meets Hyorin at school and asks for the full story, but Hyorin shows no shame or regret. Chaegyeong collapses in front of her friends…
Shin (Ju Jihun) says he will give up being Crown Prince. Chaegyeong (Yun Eunhye) is frustrated because she doesn’t know what Shin is thinking. As Chaegyeong tries to be nice to Shin and get closer to him, she finds more and more of Hyorin’s (Song Jihyo) footprints around him. It gets to the point where she fights with Shin and cries.
Through the granting of the title of King to Crown Prince Su, Hwayeong (Shim Hyejin) and Yul (Kim Jeonghun) expectantly wait to move into the palace. With the appearance of a new power, sides start being taken in the palace. The Queen (Yun Yuseon) and Hwayeong are busy sizing each other up. The Queen Dowager (Kim Hyeja) holds the power to grant the title of King. Shin and Yul run into each other and their conflicting emotions signal the beginning of a psychological war.
Meanwhile, the Queen Dowager leaves for Jeju Island with Chaegyeong to participate in a formal palace event…
Following Her Majesty’s request, Shin (Ju Jihun), Chaegyeong (Yun Eunhye) and the Queen Dowager (Kim Hyeja) set off on a road trip. Shin and Chaegyeong entertain the Queen Dowager, who is feeling depressed.
Everyone at school is awed by Yul’s (Kim Jeonghun) change in style and Shin sees a deeper meaning behind it.
Meanwhile, the Queen (Yun Yuseon) is anxious over Hwayeong’s (Shim Hyejin) movements since she moved into the palace.
The Royal Family must take special measures against the negative publicity that the Thailand photographs have brought. Chaegyeong is given no reason, but is told she must sleep in the “Uiaehab.” She is thrown into shock when Shin appears. The wedding night they never had has arrived.
The day finally breaks after a night of ups and downs, thus ending their appointed wedding night. Yul (Kim Jeonghun) races over as soon as the sun rises. He hugs Chaegyeong (Yun Eunhye) in relief when she says that nothing happened. Shin (Ju Jihun) witnesses the hug, and is angry.
Upset over the increasing rumors about the Crown Prince and Princess, Chaegyeong’s friends go after Hyorin (Song Jihyo). Chaegyeong is ill-at-ease after learning Hyorin’s secret by chance.
Someone has left a photograph in the Crown Princess’ quarters. Chaegyeong is shocked when she sees the photograph and doesn’t know what to do. Shin and Yul run around searching everywhere when they learn Chaegyeong is missing…
Shin (Ju Jihun) drags Chaegyeong (Yun Eunhye) out of Myeonseon-dang. The feelings that they’ve kept bottled inside start to come out.
Shin’s violence toward Yul (Kim Jeonghun) starts an uproar and Hwayeong (Shim Hyejin) warns the Queen (Yun Yuseon) that won’t just let it go. The King (Park Chanhwan) severely reprimands Shin and Shin starts to rebel.
In spite of the negative rumors circulating, the Crown Prince and Princess attend a public event and at photographers’ request for a loving pose, Shin reveals his acting flair.
Meanwhile, the Queen Dowager tries to get the entire family together for a meal in the face of the recent unfortunate events.
Shin (Ju Jihun) and Chaegyeong (Yun Eunhye) go on a honeymoon. Hyorin (Song Jihyo) recalls memories with Shin and looks for mementos of their love. Ignored by Shin, Hyorin takes to heart the words of Hwayeong (Shim Hyejin) and resolves to be more determined. Yul (Kim Jeonghun) tells Chaegyeong it’s time to let Shin go. Chaegyeong is confused.
The Queen (Yun Yuseon) has been watching Hwayeong’s movements and is starting to get an idea of what she’s planning. Just then, another scandal with the Crown Prince explodes. The Royal Family is mired in another dilemma.
The King (Park Chanhwan) questions Shin’s right and ability to be Crown Prince…
Because of Hyorin’s incident, Shin and Chaegyeong grow apart again.
Chaegyeong (Yun Eunhye) gets upset at Shin (Ju Jihun), who had gone out and been unreachable all day. Shin hugs Chaegyeong as she tells him why he has to suffer alone and asks her to stay by his side, even if he isn’t Crown Prince.
Meanwhile, the Queen (Yun Yuseon) offers financial support to Hyorin (Song Jihyo).
Yul (Kim Jeonghun) asks the Queen Dowager (Kim Hyeja) for permission to go on a weekend trip for his birthday with the Crown Prince and Princess…
Criticism over whether Shin (Ju Jihun) is fit to be Crown Prince continues and even the King (Park Chanhwan) wonders if Prince Uiseong (Kim Jeonghun) might be more suitable.
Meanwhile, Hyorin (Song Jihyo) discusses her future path with Shin. Chaegyeong (Yun Eunhye) is distressed when she finds out Shin and Hyorin have plans to study abroad together. Yul (Kim Jeonghun) expresses his feelings for Chaegyeong.
Shin witnesses the two of them in an intimate pose and his jealousy flares…
Chaegyeong (Yun Eunhye) is upset by the conflict between Yul (Kim Jeonghun) and Shin (Ju Jihun) that took place at Yul’s birthday party.
Shin tries to apologize to Chaegyeong, but she refuses to accept his apology and the two of them grow further apart.
Meanwhile, negative gossip circulates about Chaegyeong’s family and how they are using her name to reap benefits. Chaegyeong hears the rumors and is having more and more difficulty dealing with life in the palace. Seeing this, Shin gives her permission to stay the night at her parents’ home.
However, the Queen (Yun Yuseon) learns of this and severely reprimands Chaegyeong, and an extremely upset Chaegyeong races out of the palace…
An unexpected turn of events throws Crown Princess Chaegyeong (Yun Eunhye) in the center of harsh criticism. Though she is at the lowest point since she moved into the palace, she is determined to stick it out by herself.
Shin (Ju Jihun) suspects her motives for acting thus and grows more uncomfortable. He orders repairs for Myeongseon-dang and the tension between him and Hwayeong (Shim Hyejin), the King (Park Chanhwan), and Yul (Kim Jeonghun) widen.
The Queen (Yun Yuseon) worries that Shin is isolating himself and meets him to speak of her hopes for him.
Taking Hyorin (Song Jihyo), who has decided to be true to her dream of becoming a ballerina, as an example, Shin decides to take charge of his future both with Chaegyeong and as Crown Prince and resolutely steps out for a formal interview.
Shin (Ju Jihun) just barely managed to cover for Chaegyeong’s (Yun Eunhye) near-fatal slip at the formal interview. The adults are furious at Chaegyeong for breaking palace law, and Shin is also angry and hurt.
This incident rekindles the Crown Princess’ scandals and Hwayeong (Shim Hyejin) decides to sacrifice Chaegyeong to save Yul (Kim Jeonghun). Chaegyeong begs the King (Park Chanhwan) for forgiveness, and Shin ignores her tears and suffering.
Shin’s right to be Crown Prince is further brought under scrutiny and the King’s trust in Prince Uiseong grows. In an attempt to stand by Chaegyeong in her suffering, Yul speaks at a family meeting…
Yul (Kim Jeonghun) is willing to break palace laws, but is determined to be loyal to his heart. Shin (Ju Jihun) argues that palace laws are the strength and life of the Royal Family and demands Yul to think logically. Though their methods are different, and the things they’ve lost are different, the person they both want to stand by is the same.
Chaegyeong (Yun Eunhye) feels deep sadness for the people who are hurting because of her, but truth and logic escape her. Meanwhile, the King (Park Chanhwan) agonizes over what to do with Yul when the elders demand that the Crown Princess be punished. Shin seeks out Hwayeong (Shim Hyejin) and warns her to leave the Crown Princess alone, but her greed leads her even further down an extreme path…
Shin (Ju Jihun) is the main suspect in the arson case. He maintains his innocence, but all the evidence and circumstances suggest otherwise. Chaegyeong (Yun Eunhye) is the only one who believes him and feels pained at his troubles. Shin takes heart from her belief in him and is able to meet the challenge with composure.
Yul (Kim Jeonghun) discovers Hwayeong’s (Shim Hyejin) role in the incident and tries to stop her, but her greed knows no bounds. Talk of getting rid of the monarchy entirely picks up momentum, and in an attempt to appease the people, the King (Park Chanhwan) suggests sending the Crown Princess away. Chaegyeong decides it is her role as Crown Princess to act in the best interest of the Royal Family and resolves to follow the adults’ wishes.
Meanwhile, Chaegyeong wants to show Shin the world she used to live in. The two create happy memories outside the palace walls, not as the Crown Prince and Princess, but as an ordinary young couple.
An unexpected twist throws Shin (Ju Jihun) into uncertainty about making it through the arson case. In the midst of the turmoil, Shin and Chaegyeong’s (Yun Eunhye) trust and dependence on each other is stronger than ever. Chaegyeong says she has studied and tried hard to become someone who is a good match for Shin, but the two are more alike than they realize.
Regardless of the results of the arson case, the King (Park Chanhwan) says that Shin is fit to be a king who is loved and respected by the people. Hwayeong (Shim Hyejin) races toward victory in self-assurance.
The Queen (Yun Yuseon) shares an intimate moment with Chaegyeong, who has taken on the characteristics of a good Crown Princess, for the first time. Having received encouragement from her mother-in-law and a token of her husband’s love, Chaegyeong steps out to stand by her newfound family and life…