"Lupin Zero" is a prequel to the iconic "Lupin III" franchise, exploring the early years of the titular master thief, Arsène Lupin III, during his adolescence in 1960s Japan. The series delves into Lupin's formative years, showcasing his initial steps into a life of crime and the development of his signature charm, wit, and daring. Set against a backdrop of post-war Japan, the narrative captures the cultural and societal shifts of the era, blending historical context with the franchise's trademark heist-driven action.

The story begins with Lupin as a middle school student, already displaying a knack for mischief and a disdain for authority. Despite his lineage as the grandson of the legendary thief Arsène Lupin, he initially resists embracing his family's criminal legacy. However, his life takes a turn when he encounters a mysterious and skilled thief named Yoko, who becomes both a rival and a mentor figure. Yoko challenges Lupin to step out of his comfort zone and embrace his potential, setting him on a path toward becoming the world-renowned thief he is destined to be.

Throughout the series, Lupin navigates a series of high-stakes heists, often targeting wealthy elites and corrupt figures. His adventures are marked by clever schemes, narrow escapes, and a growing sense of confidence in his abilities. The narrative also introduces key elements that foreshadow his future, such as his fascination with gadgets, his ability to outthink opponents, and his penchant for theatricality. Supporting characters, including a young Daisuke Jigen, provide glimpses into the relationships that will later define Lupin's life as an adult.

The series balances episodic heist plots with an overarching exploration of Lupin's character, highlighting his struggles with identity, family expectations, and the moral ambiguities of his chosen path. By the end, "Lupin Zero" offers a compelling origin story that enriches the broader "Lupin III" universe, providing insight into the origins of one of anime's most enduring and beloved characters.