"Phantom of the Idol" centers on the lives of two individuals whose paths cross in the world of Japanese idol culture. The story begins with Yūya Niyodo, a member of the male idol duo ZINGS, who has grown disillusioned with his career. Despite his talent, Yūya lacks passion and merely goes through the motions, treating his idol work as a job rather than a calling. His apathy contrasts sharply with the vibrant energy expected of idols, leaving him disconnected from both his fans and his fellow performers.

The narrative takes a dramatic turn when Yūya encounters Asahi Mogami, the ghost of a former idol who died tragically young. Asahi was once a beloved and dedicated idol, known for her boundless enthusiasm and genuine love for performing. Unable to move on to the afterlife, she becomes attached to Yūya, seeing an opportunity to relive her idol dreams through him. Asahi possesses Yūya during his performances, transforming his lackluster stage presence into something electrifying and captivating. This supernatural arrangement forces Yūya to confront his own insecurities and rediscover his passion for performing.

As the story progresses, the dynamic between Yūya and Asahi evolves. Yūya begins to appreciate the joy and fulfillment that come from connecting with an audience, while Asahi grapples with her unresolved feelings about her untimely death and her lingering attachment to the world of idols. The series explores themes of identity, purpose, and the pressures of fame, delving into the personal struggles of both characters as they navigate their shared journey.

The supporting cast includes other members of ZINGS, rival idols, and industry professionals, each contributing to the broader exploration of idol culture. The manga balances moments of humor and heartwarming camaraderie with deeper emotional arcs, creating a multifaceted portrayal of the idol industry. Through its blend of supernatural elements and grounded character development, "Phantom of the Idol" offers a unique perspective on the challenges and rewards of pursuing a career in the spotlight.