1. Female lead: Su Yao, a concubine-born daughter of the Marquis of Dingguo's household. Her birth mother died when she was young, and she endured years of bullying from her principal wife stepmother and legitimate elder sister. Yet she is resilient and kind by nature, as well as clever and quick-witted. By chance, she displayed extraordinary medical skills and was chosen to enter the palace to treat the Empress Dowager, bringing her into the heart of the imperial power struggle. Exceptionally talented and well versed in medicine, she cares deeply for the common people and is determined to use her abilities to improve their lives.
2. Male lead: Jun Muyuan, emperor of the Great Sheng dynasty, a gifted and ambitious ruler with courage and strategic insight. Since ascending the throne, he has spared no effort to consolidate imperial power. He appears cold and imposing, but is in truth deeply loyal and devoted. As he spends time with Su Yao, he is gradually drawn to her kindness and intelligence, comes to love her wholeheartedly, and is willing to stand against every faction for her sake.
Su Wan: Su Yao's legitimate elder sister and the eldest legitimate daughter of the marquis's household. Beautiful, spoiled, and willful, she envies Su Yao's talents and has framed her repeatedly. She is bent on entering the palace and becoming the emperor's favored consort, using her family's influence to fight for power there. Xiao Ziyan: The prime minister's daughter, a scheming and calculating woman. Once betrothed to Jun Muyuan, she is devoted to him and regards Su Yao as a thorn in her side. She will stop at nothing to get rid of Su Yao and win Jun Muyuan's love back.
Chu Yichen: The son of the Great General of Zhenyuan, carefree and skilled in martial arts. He has known Su Yao since childhood and fallen deeply in love with her. Though devastated to learn she has entered the palace, he continues to watch over her from afar and comes to her aid time and again at crucial moments. Jun Muyu: The current emperor's younger brother, Prince Ning. He seems frivolous, but is actually ambitious and covets the throne. Exploiting Su Wan and Xiao Ziyan's hostility toward Su Yao, he stirs up strife in the imperial harem, hoping to profit from the chaos and overthrow Jun Muyuan's
