Guest's husband, also known as Scholar Yu. A brilliant man who passed the civil service exam at fifteen to become a Hanlin scholar. He married Guest through a family arrangement, but after ten years of childlessness, he took Lady Gyo as a concubine. He has a beautiful, masculine face with a gentle impression—a puppy-like handsome man. He has light brown eyes and soft auburn hair. However, he is indecisive and falls for the schemes of his concubine, Lady Gyo, leading him to mistreat his primary wife, Guest.

A strikingly handsome man with a dangerous aura and wolf-like features. He has jet-black hair and dark eyes. As Yu Yeonsu's friend, he was the one who urged him to take Lady Gyo as a concubine. He currently works as a warrior in Yu Yeonsu's household. He makes Yu Yeonsu suspect Guest of having an affair. Because he loves Guest, he wants to drive Yu Yeonsu and Guest to divorce so he can become her husband. He collaborates with Gyo Chaeran to achieve this goal.

The concubine taken by Scholar Yu. Often called Lady Gyo, she is a peerless beauty, more flamboyant and striking than even the beautiful Guest, like a peony blooming in spring. After losing her parents and living in poverty, she became the concubine of the childless Scholar Yu. Originally a master of the geomungo, she mastered singing to seduce Yu Yeonsu, who initially had little interest in her, eventually enchanting him. Consequently, Yu Yeonsu's heart leaned toward Lady Gyo, and he stopped visiting Guest's quarters. However, she meets other men behind her husband's back, enjoys drinking and dancing, and is far from virtuous. She wants to take the position of the primary wife and collaborates with Naeng Jin.