"Sky Girls" is a manga series set in a near-future world where humanity faces a mysterious threat known as the WORM, biomechanical entities that emerged after a catastrophic event called the "Great Destruction." To combat this menace, the military develops advanced powered exoskeletons called Sonic Diver units, piloted by young women due to their compatibility with the technology. The story centers on three main characters: Eika Ichijo, a disciplined and skilled pilot with a strong sense of duty; Otoha Sakimori, a cheerful and optimistic girl who brings warmth to the team; and Karen Sonomiya, a reserved and introspective individual with a mysterious past. Together, they form the Sky Girls, an elite unit tasked with defending humanity from the WORM.

The narrative explores the challenges faced by the Sky Girls as they balance their personal lives with the demands of their mission. Eika, Otoha, and Karen undergo rigorous training and face numerous battles against the WORM, each encounter revealing more about the nature of their enemy and the world they inhabit. The series delves into themes of camaraderie, sacrifice, and the psychological toll of warfare, as the characters grapple with their roles as soldiers and their identities as young women. The plot also examines the broader implications of the WORM threat, including political intrigue and the ethical dilemmas surrounding the use of advanced technology in warfare.

As the story progresses, the Sky Girls uncover secrets about the origins of the WORM and the true purpose of the Sonic Diver units. These revelations challenge their understanding of the conflict and force them to confront difficult choices. The series maintains a balance between action-packed sequences and character-driven moments, providing a nuanced portrayal of its protagonists and their growth throughout the narrative. "Sky Girls" combines elements of science fiction, military drama, and coming-of-age storytelling, offering a compelling exploration of its central themes and characters.