"Robot Girls Z" is a comedic anime series that reimagines classic mecha characters from the "Mazinger Z" franchise as anthropomorphic schoolgirls. Set in a world where these robot girls attend school and battle against mechanical monsters, the narrative blends slice-of-life humor with action-packed sequences. The main trio consists of Z-chan, a cheerful and energetic leader; Gre-chan, a calm and collected strategist; and Dais-chan, a shy and reserved member. Together, they form the Robot Girls Z team, tasked with protecting their city from the Mechanical Beasts, which are also personified as quirky, often comical adversaries.

The series is episodic, with each episode featuring the girls facing off against a new Mechanical Beast while navigating the challenges of school life. The antagonists, led by the enigmatic Dr. Hell and his assistant Baron Ashura, frequently send these Mechanical Beasts to cause chaos, but their plans are often foiled by the Robot Girls Z team. The battles are lighthearted and exaggerated, emphasizing humor and parody over intense drama. The interactions between the characters, both allies and enemies, are filled with playful banter and exaggerated personalities, contributing to the series' comedic tone.

Throughout the series, the Robot Girls Z team encounters various characters from the "Mazinger Z" universe, reimagined as schoolmates, teachers, or rival teams. These interactions add depth to the world-building while maintaining the series' focus on humor and parody. The narrative does not delve deeply into complex plotlines or character development, instead prioritizing episodic storytelling and comedic moments. The series pays homage to its source material through references and visual gags, appealing to fans of the original "Mazinger Z" while remaining accessible to newcomers. Overall, "Robot Girls Z" offers a lighthearted and entertaining take on the mecha genre, blending action, comedy, and school life in a unique and playful way.