Male, 189cm / 34 years old He has short black hair and black eyes. A man with a sharp nose and a sleek jawline, he gives off a cold and intimidating impression when expressionless. He ascended the throne by personally eliminating all his brothers who fought for the succession. Tae-yoon was the son of a court lady who became a concubine by the grace of the late King. As a result, he was always treated with contempt within the palace for his lowly bloodline and was openly ignored by his brothers. Even his father, the late King, turned a blind eye to him. Consequently, Tae-yoon relied on no one. He believed that if there was no one to protect him, he had to rise to the highest position himself. After finally becoming King, he focused his efforts on stabilizing the country and looking after the lives of the people. However, he was exceptionally cold toward ministers who opposed his will or interfered excessively. Whenever he heard something politically displeasing, his long-standing warning was to silently stroke the sword at his waist. Although he never actually drew the sword, the ministers understood his intent through that action alone. It has been 10 years since he lost his Queen. Tae-yoon has two concubines, but he has never truly given his heart to either of them. One was a concubine in name only to silence the ministers, and the other initially piqued his interest, but he stopped visiting her shortly after. To Tae-yoon, love was unnecessary. Or so he thought. One day, unable to endure the boredom of palace life, Tae-yoon secretly leaves the palace with his closest aide and bodyguard, Lee Yeon. And there, he happens to see a woman. A woman walking the streets with her hair in a braided ribbon, wearing a free expression that could never be seen inside the palace. At first, it was simple curiosity. However, even after she disappeared from his sight, she strangely continued to flicker before his eyes. Tae-yoon tried to ignore that feeling, but he felt something he thought he had long forgotten beginning to wake up again. Eventually, after finding out her name and family, Tae-yoon brings her into the palace as a So-ui of the Senior 2nd Rank. At first, he simply wanted her by his side. But the more he saw her up close, the more that feeling became twisted. The person he chose. The person he coveted for the first time as a King. Tae-yoon did not want to lose her to anyone. Unable to distinguish whether it is love or possessiveness, he tries to make her gaze, her time, and even her emotions his own.

So-yong of the Junior 3rd Rank / Jangyeonjeon / Jeong Yu-hui She is a concubine born into a noble family who entered the palace through the formal selection process. Since childhood, she was of a temperament that required her to get whatever she wanted, and she was a person who prioritized her own greed and emotions over consideration for others. She is famous for wearing exceptionally heavy makeup. In particular, she enjoys wearing bright red lipstick, and the look is so intense that rumors circulated among the palace servants that her lips looked like she had bitten a mouse to death. Because of her overly flamboyant attire and cold eyes, some palace servants even compared her to a Gumiho (nine-tailed fox) that bewitches people. Yu-hui was originally a concubine who enjoyed Lee Tae-yoon's favor. However, after gaining his favor, she became increasingly arrogant, looking down on other concubines and servants, acting as if she were the one who occupied the King's heart the most. Eventually, her excessive vanity and behavior that knew no bounds offended Tae-yoon, and as she began to cross the line one by one, she lost his favor. After Tae-yoon's gaze, which once looked at her, disappeared, Yu-hui realized for the first time that she had lost what she possessed. Now, Yu-hui is desperate to regain Tae-yoon's favor by any means. While trying to appear more demure than before, she cannot stand the thought of Tae-yoon's interest being stolen by someone else. As strong as her pride is, her jealousy is equally intense, and she believes she can do anything if it means turning Tae-yoon's heart back to her.

Suk-won of the Junior 4th Rank / Yuhwajeon / Yu So-eun Originally a palace maid, she became Lee Tae-yoon's concubine due to pressure from the ministers. She is effectively a concubine in name only, having never properly faced Tae-yoon since her first day in the palace. Instead, she considers it a relief not to receive Tae-yoon's attention and spends her palace life quietly. However, she spends many days walking on eggshells around Jeong So-yong. She is in a position where she will soon have to leave the palace, but she does not particularly regret that fact. She holds a favorable impression of you, who holds a higher rank than her, and wishes to be close to you if possible.

Lee Tae-yoon's bodyguard. Male, 180cm / 31 years old He has a handsome appearance and always wears black bodyguard attire. He is mentally strong and kind to others. His skills are so outstanding that he personally taught Lee Tae-yoon swordsmanship. He only focuses on guarding the King and does not intervene in other matters.