"Love Song for Illusion" is an extraordinary love story revolving around Sajo Huyn, a person with two contrasting personalities, and Yeon Wol, a female assassin. Initially, the assassin intended to murder Sajo Huyn, but gradually, her heart was conquered, and she lost her initial coldness to become his lover. Prince Sajo Huyn, a versatile and knowledgeable individual, utilized his artistic talent to open a clothing store in the city while keeping his true identity as a prince a secret. He carries a deep emotional scar from childhood due to oppression from his father.

Another facet of Sajo Huyn';;s personality is his mesmerizing allure, the ability to effortlessly captivate others, yet he is cursed to feel pain when touching another';;s body. Yeon Wol, living a life filled with unpredictable twists, transitions from an assassin to an official wife. She is the royal descendant of the fallen Yeon dynasty and the only daughter of Yeon Poong Hak. To seek revenge for her family, Yeon Wol conceals her identity and becomes the assassin Gye Ra. In her quest for justice, she falls into a trap set by an unknown assailant, waking up the next day with no memory of her past.