Grand Prince Suyang attempts to build an alliance with Kim Jong-seo, the trusted official of his brother, King Munjong. He proposes a marriage between his eldest daughter, Lee Se-ryung, and Kim Jong-seo's younger son, Kim Seung-yoo. Learning of this, Se-ryung's curiosity regarding her prospective husband is piqued, and on hearing that Seung-yoo is going to take over as the tutor of her cousin, Princess Gyeonghye, she persuades her to swap places so that she can catch a glimpse of her intended. Her first impression is not favorable and she is convinced that he is an arrogant womanizer. Later, as she attempts to master her current obsession with riding a horse, Seung-yoo arrives in the nick of time to rescue her from being thrown off a precipice.
Meanwhile, Kim Jong-seo rejects Suyang's proposal because he knows the Grand Prince's aspirations regarding the throne and allies himself firmly with King Munjong. The King is impressed with Seung-yoo as a capable tutor and sees merit in having him as a son-in-law. He announces that Seung-yoo has been selected as a potential prince consort. Seung-yoo, who still believes Se-ryung is the Princess, is glad of the decision because of his growing feelings for her. Beginning to understand her passion to escape the confines of her cloistered life, he offers to teach her how to ride. Their blissful time together is cut short by assassins sent by Suyang to kill Seung-yoo as revenge against Kim Jong-seo. Seung-yoo is injured and as Se-ryung risks her life to save him, the Chief Magistrate of the capital's Police Bureau, Shin Myeon, chances to pass by and saves them. Shin Myeon also happens to be Seung-yoo's best friend, along with Jeong Jong, whose noble family has fallen on harsh straits. Even though Shin Myeon senses his friend's growing admiration for Se-ryung, he too finds himself drawn to the brave and beautiful girl. His dilemma grows when Grand Prince Suyang offers Se-ryung's hand in marriage to him in the hope of building an alliance with his politician father.
Se-ryung learns that Seung-yoo is being considered for the position of prince consort and is devastated. Gyeonghye understands the political import of marrying Seung-yoo and orders her to not meet Seung-yoo anymore, suspecting that the two are falling in love. However, Seung-yoo and Se-ryung meet outside the palace once again. Following their time together, Seung-yoo writes a letter to Se-ryung and sends it to the real Princess Gyeonghye, who, understanding that they met despite her orders, is furious. At the next lesson, she locks up Se-ryung and takes her place, thereby revealing the deception to Seung-yoo, but she hides Se-ryung's identity from him by calling her a palace maid who took her place.
The letter discarded by Gyeonghye falls into the hands of Suyang. Using the letter as evidence, he declares that Seung-yoo is unfit to be the prince consort and insinuates that he dishonored the Princess by meeting her outside the palace. When interrogated, Seung-yoo says he did not meet the Princess outside but hides Se-ryung's part in it to spare her danger. Learning of the danger to Seung-yoo's life, Se-ryung begs Gyeonghye to intercede for Seung-yoo. Despite her intercession, the penalty for Seung-yoo's transgression is death. Suyang discovers Se-ryung when she secretly visits Seung-yoo in prison and is horrified to learn of their dalliance. Relieved that Seung-yoo does not know who she is, he agrees to save Seung-yoo if she never meets him again and never reveals her identity to him. Kim Jong-seo, desperate to save his son, approaches Suyang for help and agrees to pay the humiliating price of resigning from his position. Seung-yoo's sentence is commuted to temporary exile. Jeong Jong is chosen as prince consort, bringing a drastic change in his fortunes. He is smitten with the Princess from the beginning; however, she detests him. Se-ryung's relationship with Gyeonghye is also strained, with the Princess blaming her cousin for all the misfortunes she has undergone.
King Munjong collapses on the day of his daughter's wedding and his health takes a turn for the worse. Seung-yoo is summoned back by his elder brother, in order to assist their father in safeguarding the interests of the King. Seung-yoo runs into Se-ryung on his return but coldly severs all ties with her. However, Se-ryung's concern for her cousin coupled with the fact that Jeong Jong is Seung-yoo's friend, forces the two to meet again. Both find it hard to repress their feelings and finally Seung-yoo declares his love for her. Meanwhile, at exactly the same time, King Munjong dies. Suyang and his cronies arrive at the palace, jubilant that they can now control the new King Danjong. However, their plans are thwarted by Kim Jong-seo, who was reinstated by the late King to protect his son from Suyang's machinations.
Furious, Suyang prepares to stage a coup against Kim Jong-seo. Se-ryung stumbles on the plot too late and is foiled in her attempts to warn Seung-yoo and his family. Supported by Shin Myeon, Suyang ruthlessly murders his opponents, including Seung-yoo's father and brother. Shin Myeon, believing that Seung-yoo is dead, stops the other men from beheading him claiming he wishes to do it himself. As he is about to bury him, Shin Myeon realizes that Seung-yoo is (barely) alive and attempts to kill him, but in the end turns around and leaves, giving Seung-yoo the chance to escape with his life.
Seung-yoo wakes up and walks into the city to find that his father had been beheaded. Reeling from his best friend's betrayal, he tries to kill Suyang, only to be shocked by the discovery that Se-ryung is his daughter. Seung-yoo is sentenced to death, but a last minute intercession by the young King saves his life and he is exiled to Ganghwa Island, along with the rest of Suyang's enemies. When Se-ryung visits him in prison on the eve of his exile, his fury gets the better of him and he nearly chokes her to death. Se-ryung admits her identity and begs him to survive, even if it is just so that he can kill her.
En route Ganghwa Island, the ship is sunk to ensure that none of Suyang's enemies survive. However, aided by a fellow prisoner, Jo Seok-joo, Seung-yoo manages to escape and return. Taking refuge at a gisaeng house owned by Seok-joo, Seung-yoo plots his revenge. Meanwhile, Se-ryung learns that Seung-yoo's ship sank. Despite her mourning, her parents fix the date of her wedding with Shin Myeon.
In an attempt to bait Suyang, Seung-yoo kidnaps Se-ryung on the day of her wedding. He is mercilessly cruel to her, and reveals her father's part in the sinking of the ship. Suyang shows up to claim his beloved daughter but he survives Seung-yoo's arrow because of his armor. Meanwhile, Shin Myeon shoots an arrow at Seung-yoo, which is intercepted by Se-ryung who takes the brunt of it. Shaken by her sacrifice, Seung-yoo is shell shocked and he has to be forcibly dragged away by Seok-joo and Noh-gyul.
Se-ryung is taken home and Shin Myeon is suspicious because she took the arrow on behalf of her kidnapper. The encounter with Seung-yoo changes Se-ryung's attitude towards her father and Shin Myeon, as she is now fully aware of the extent to which they will go for power. Seung-yoo reveals that he is alive to Jeong Jong, and starts assassinating those who were privy to his family's massacre. He leaves behind the alias of his deceased father, Great Tiger, at each site to stir fear among his enemies. Se-ryung's attempts to atone for her father's crimes gradually melts Seung-yoo's anger, especially when he learns that she saved the lives of his sister-in-law and niece. Suyang forces King Danjong to abdicate and takes the throne himself, becoming King Sejo. Se-ryung refuses to be conferred as princess and continues to bravely defy her father.
Seung-yoo gives up his vigilante assassinations at the behest of his former teacher, who urges him to join the larger cause of dethroning Sejo and restoring Danjong. Se-ryung inadvertently learns of the plot and is caught in a terrible dilemma. Saving her father comes at the cost of her love and vice versa. However, the rebellion that was led by the six scholars of the Hall of Worthies, including Seung-yoo's teacher, fails, leading to their deaths and the exile of Princess Gyeonghye and Jeong Jong.
Seung-yoo manages to escape, but Shin Myeon discovers his identity. King Sejo learns that Seung-yoo is alive and that Se-ryung may have had knowledge of the plot. The rift between father and daughter grows. In a symbolic move, Se-ryung cuts her hair and renounces her ties with her father. When she takes refuge in a temple after leaving the palace, Seung-yoo takes her with him to the gisaeng house, but she is forced to surrenders herself when Shin Myeon and his guards nearly tear apart the place. In his rage, King Sejo sentences her to become Shin Myeon's slave. Seung-yoo and his friends rescue her in the nick of time. Shin Myeon refuses to give up his quest to possess Se-ryung and follows the pair to Princess Gyeonghye and Jeong Jong's place of exile. Shin Myeon comes to learn that Jeong Jong is plotting yet another rebellion. He is arrested and executed, leaving behind a devastated and pregnant Gyeonghye.
The leaders with whom Seung-yoo continues the rebellion refuse to accept Se-ryung because of her link to King Sejo. Seung-yoo and Se-ryung pledge their love as husband and wife and agree to separate till the battle is over. However, when Shin Myeon plans to use Se-ryung as bait to lure Seung-yoo, she escapes and warns her husband. In the battle that follows, Shin Myeon is killed and Seung-yoo's side wins. Seung-yoo moves forward with his plan to assassinate the King and nearly succeeds, but for a momentary distraction caused by learning of Se-ryung's pregnancy. Seung-yoo is sent to prison and Se-ryung goes to see him, wanting her baby to at least know who their father is. Seung-yoo is close to death and Se-ryung accepts her fate. However, Se-ryung's mother orchestrates their escape.
Years later, Seung-yoo has become blind, but he lives a happy life with Se-ryung and their daughter. In the backdrop of their bliss, we see an aged King Sejo who has let go of his bitterness and who watches his daughter in secret.
The eldest and favorite daughter of Grand Prince Suyang, she is a bright and sweet person, with an adventurous streak. She persuades her cousin, Princess Gyeonghye, to exchange places with her during a tutoring session with Kim Seung-yoo, upon learning of her father's initial plans to arrange her marriage with him. A harmless prank to sneak a peek at her intended husband spirals out of control as they fall deeply in love with each other, ignorant of the deep and deadly political enmity that slowly develops between their fathers.
The younger son of Kim Jong-seo, he is a carefree scholar in the Royal Academy, whose main interests are having a good time with the ladies and spending time with his friends, Shin Myeon and Jeong Jong. He meets his match in the spirited Lee Se-ryung. As he falls harder for her, his love is put to the ultimate test when he learns that Se-ryung is not the Princess, but rather the daughter of his father's greatest enemy.
Younger brother of King Munjong, he has his eyes firmly fixed on the throne. He is a ruthless politician, who will not countenance anyone standing in his way. Lee Se-ryung, his eldest daughter, is his weakness, but when she falls in love with the son of his enemy, he has no compunctions in eliminating Kim Seung-yoo and his entire family.
Lee Se-ryung's cousin and friend, she is King Munjong's only legitimate daughter. She is indulged by her father, but the sudden knowledge of her father's illness and Grand Prince Suyang's threat to her young brother destroys her sheltered and uncomplicated life. She finds herself trapped in an unwanted marriage with Jeong Jong, but as her uncle systematically destroys her allies one by one, she begins to find solace and comfort in her husband's love.[7][8]
Chief Magistrate of the capital's Police Bureau, he enjoys a deep camaraderie with Kim Seung-yoo and Jeong Jong. When he saves Kim Seung-yoo and Lee Se-ryung from an attack by assassins, the girl's bravery arouses his interest. What begins as a crush on his best friend's lover has devastating consequences when his father strikes an alliance with Grand Prince Suyang and marriage is on the cards for both of them.
The gentle and perpetually debt-ridden friend of Kim Seung-yoo and Shin Myeon. His fortunes take a turn for the better and in an amazing twist of destiny, he finds himself as the prince consort. However, his new bride, helplessly carrying the burden of her father's illness and the danger to her brother's life, initially has no time or inclination for his love. Just as his relationship with Princess Gyeonghye begins to improve, his life is endangered in an attempt to resist Grand Prince Suyang.
A brilliant general who serves as the Left State Councillor and King Munjong's most trusted advisor, he alienates Grand Prince Suyang when he accepts Princess Gyeonghye instead of Suyang's daughter as bride for his younger son. He pays the price of his misalliance with his life and the destruction of his family.
Supporting characters
Um Hyo-sup as Yi Gae, former teacher of Kim Seung-yoo, Shin Myeon and Jeong Jong
Heo Jung-kyu as Kim Seung-gyu, Kim Seung-yoo's elder brother
Lee Joo-seok as Grand Prince Anpyeong
Kim Seo-ra as Lady Yun, Grand Prince Suyang's wife
On September 2, 2012, members of the cast, namely Park Si-hoo, Song Jong-ho and Hong Soo-hyun, attended a promotional concert at Tokyo International Forum to promote the airing of the series on Japanese satellite channel BNK-BS.[22]
It aired in the Philippines on the GMA Network from November 19, 2012 until February 7, 2013.[23]
It aired in Sri Lanka on TV Derana under the title Sihina Kumara (සිහින කුමරා) from March 2014.[24]
