To become one of the entertainment industry’s most sought-after songwriters, you have to have talent, inspiration, and passion. But to reach the level of popularity obtained by Ha Rip, you also have to be willing to make certain sacrifices.

Ten years ago, as a struggling artist, Ha Rip found himself wondering if he would ever make his mark on the world. On the verge of giving up, he found himself face to face with the Devil himself, who offered to give Ha Rip everything his heart desired for a price. Desperate, Ha Rip agreed to sell his soul to the Devil, and so began a decade of unprecedented success.

But when those ten years are almost up, and the Devil has come to collect his due, he learns that his success and fame are the results of taking Lee Kyung’s talent and life. Learning that every deal you make with the Devil comes with a hefty price, Ha Rip tries to barter with his life but will that be enough to satisfy the debt he still owes?

Lee Gon is the third Korean emperor of his generation. His citizens regard him as the perfect leader. But behind this flawless appearance, hides a deep wound. When he was eight years old, his father was murdered before his eyes following a coup. Today, instead of respecting his filial duty, he prefers to escape the palace to attend university conferences. During one of his escapades, he sees himself propelled into a parallel world where he meets Jeong Tae Eul, an inspector with whom he teams up with to defeat the criminals but also close the door between their two worlds

Kang Su Hyun is a star producer, who trains idols with her own philosophy and intuition. For an unknown reason, she gets fired from Pandora Entertainment. At home, Kang Su Hyun is the breadwinner of her family. Her husband, Sim Jun Seok, is a full time homemaker and takes care of their son Sim Jin U. Prior to becoming the homemaker, Sim Jun Seok worked as a music producer, but, after his son lost his hearing in a childhood car accident, he quit his job to take care of him and their home full time.

To get back on her feet, Kang Su Hyun begins a new project to create a star. She picks Yoo Jin U as her trainee. Yoo Jin U has trained to become an idol for the past 10 years and he carries all sorts of baggage with him like his parents' debt and his past career. Right when Yoo Jin U was about give up on his dream, Kang Su Hyun selected him as her trainee. Yoo Jin U now restarts his training in earnest. While, Sim Jun Seok's desire to return to his job as a music producer grows, Kang Su Hyun tells him to work as Yoo Jin U's producer.

Lee Ma Ha is a member of the new K-pop girl group Tea Party, formed by Ji Hak, who was once the manager of the famous boy group Shax, but resigned after the sudden disappearance of member Eun Jo in the middle of a concert. Prior to joining Tea Party, Ma Ha was a member of the group Omega III, which disbanded on its debut day due to a tragic incident involving a former trainee at the group's company. This led Ma Ha to support herself by performing as an impersonator of the popular solo singer La Li Ma, gaining her public notoriety.

Starting anew with Tea Party, Ma Ha finds herself repeatedly crossing paths with Kwon Ryok, the center and most popular member of Shax who is still haunted by Eun Jo's disappearance three years later. While Ryok initially dislikes Ma Ha due to her imitation of Li Ma, the two eventually begin to grow interest in one another and start a secret relationship that could put both of their careers in jeopardy.

Meanwhile, Lee Yu Jin, Ma Ha's loyal friend who is the center of the rising boy group Sparkling, has been in love with Ma Ha since their idol trainee days. When he notices the budding relationship between Ma Ha and Ryok, he determines to protect her from Ryok and lead Sparkling to beat out Shax as the most popular boy group in the industry.