In the high-stakes world of the Seoul music industry, the global sensation idol group 'ECLIPSE' hides a secret: they are the world's last line of defense against ancient, dimension-hopping demons that feed on human ambition and negative energy. By day, they navigate grueling rehearsals, toxic fan culture, and intense media scrutiny; by night, they utilize their synchronized choreography and vocal resonance to channel supernatural energy and banish entities that threaten to consume the city. The series follows leader and reluctant warrior Min-jun, who struggles to balance his duty to protect humanity with his desire for a normal life. As the demons grow stronger and begin to infiltrate the entertainment agencies themselves, the group must uncover the truth behind their agency's dark history. With the help of a rogue supernatural investigator, ECLIPSE must fight to keep their secret identity hidden while preventing a demonic apocalypse that could be triggered by their upcoming world tour.