"Saber Marionette" is a manga series set in a distant future where Earth has become uninhabitable, and humanity has colonized a new planet named Terra II. Due to a gender imbalance caused by a virus that wiped out most of the female population, society is now entirely male-dominated. The story centers around Otaru Mamiya, a young man living in the nation of Japoness, who stumbles upon three advanced female androids known as Marionettes: Lime, Cherry, and Bloodberry. These Marionettes possess unique personalities and emotions, a rarity among androids, due to a special "Maiden Circuit" that grants them human-like qualities.

Lime, the first Marionette Otaru encounters, is cheerful, energetic, and childlike, embodying innocence and curiosity. Cherry, the second, is calm, intelligent, and nurturing, often serving as the voice of reason. Bloodberry, the third, is fiery, strong-willed, and combat-oriented, representing strength and determination. Together, they form a close bond with Otaru, who becomes their protector and guide in a world where androids are often seen as mere tools.

The narrative explores themes of humanity, identity, and the ethical implications of artificial intelligence. As Otaru and the Marionettes navigate their relationships, they face opposition from various factions, including the militaristic Gartland nation, which seeks to exploit the Marionettes for their advanced technology. The conflict escalates as the true origins of the Marionettes and their Maiden Circuits are revealed, tying them to a deeper mystery about Terra II's history and the remnants of Earth's civilization.

Throughout the series, the characters grapple with their roles in a society that struggles to reconcile its reliance on technology with its longing for human connection. The Marionettes' evolving emotions and their interactions with Otaru and others highlight the blurred lines between machine and human, raising questions about what it means to truly be alive. The story balances action, humor, and introspection, creating a compelling exploration of its central themes while maintaining a focus on the characters' growth and relationships.