One day, a good-looking man in martial arts robes appears in front of Jeom So-eui, the manager of the martial arts idol group Noble Alliance. He introduces himself as Wi Hwajin, the Heavenly Demon, and declares that he wants to be an idol.

Jeom So-eui leaves this problem in the hands of the CEO K-tsch Entertainment (the company behind Noble Alliance), a man who's obsessed with martial arts and suspiciously rich, but the CEO decides to let Wi Hwajin join the group!

Wi Hwajin claims that he represents the orthodox sects and joins Noble Alliance! However, he has an ulterior motive that even Jeom So-eui doesn't know about...

Based on the original novel The Heavenly Demon Became an Idol by Ul Eomma.