"Zone of the Enders: Idolo" is a prequel to the "Zone of the Enders" video game series, set in a futuristic world where humanity has colonized Mars. The story centers on the conflict between the Earth government, UNSF, and Martian rebels, BAHRAM, who seek independence from Earth's control. The narrative explores the development of the Orbital Frame, a powerful humanoid mecha, and its impact on the war.

The protagonist, Radium Lavans, is a skilled test pilot working for the UNSF. He is tasked with piloting the prototype Orbital Frame, Idolo, which is powered by a mysterious and unstable energy source known as Metatron. Radium's life takes a dramatic turn when he encounters a Martian girl named Elena Weinberg, a BAHRAM operative. Elena is determined to steal Idolo to aid the Martian rebellion, but her encounter with Radium complicates her mission.

As the story progresses, Radium becomes increasingly conflicted about his role in the war. His loyalty to the UNSF is tested as he witnesses the devastating consequences of Idolo's power and the ethical dilemmas surrounding its use. Meanwhile, Elena struggles with her own mission, torn between her duty to BAHRAM and her growing empathy for Radium. The narrative delves into themes of war, sacrifice, and the human cost of technological advancement.

The climax of the series revolves around a pivotal battle between UNSF and BAHRAM forces, where Radium and Elena are forced to confront their choices. The destructive potential of Idolo becomes fully realized, leading to catastrophic consequences for both sides. The story concludes with a somber reflection on the futility of war and the personal toll it takes on those involved.

"Zone of the Enders: Idolo" provides a grounded and character-driven exploration of the events leading up to the "Zone of the Enders" universe, focusing on the moral complexities of warfare and the individuals caught in its crossfire. The series serves as a foundation for understanding the broader conflict between Earth and Mars, while offering a poignant look at the human stories behind the mecha battles.