"Zettai Reido Idol" centers on the life of Hikari Minami, a young woman who dreams of becoming a top idol despite her lack of natural talent. The story begins with Hikari joining the prestigious talent agency, Stardust Promotion, where she is placed in a training program alongside other aspiring idols. Unlike her peers, Hikari struggles with singing, dancing, and even basic stage presence, making her journey particularly challenging. However, her unwavering determination and relentless effort set her apart, earning her the nickname "Absolute Zero Idol" due to her perceived lack of potential.

The narrative explores Hikari's growth as she faces numerous obstacles, including intense competition, harsh criticism, and self-doubt. Her relationships with other characters, such as her supportive but strict mentor, Aoi Shindo, and her rival-turned-friend, Rina Tachibana, play a significant role in her development. Aoi, a former idol herself, pushes Hikari to her limits, often questioning whether her efforts will ever pay off. Rina, on the other hand, initially views Hikari as a hindrance but gradually comes to respect her perseverance.

As the story progresses, Hikari's hard work begins to yield results, and she starts to gain recognition within the agency. Her performances, though still imperfect, resonate with audiences due to her genuine passion and authenticity. The series delves into the behind-the-scenes realities of the idol industry, highlighting the pressures and sacrifices required to succeed. Themes of perseverance, self-belief, and the importance of effort over innate talent are central to the narrative.

The manga also introduces subplots involving other trainees, each with their own struggles and aspirations, providing a broader perspective on the idol world. These characters, such as the prodigious but emotionally distant Yuki Nakamura and the ambitious yet insecure Miku Sato, add depth to the story and create a dynamic ensemble cast. Their interactions with Hikari further emphasize the collaborative and competitive nature of the industry.

"Zettai Reido Idol" balances moments of humor, drama, and inspiration, offering a realistic portrayal of the idol industry while maintaining an engaging and heartfelt narrative. Hikari's journey serves as the emotional core of the series, illustrating the transformative power of dedication and the pursuit of one's dreams despite overwhelming odds.