"All Purpose Cultural Cat Girl Nuku Nuku" centers around Ryunosuke Natsume, a young boy whose life takes a dramatic turn when his father, Kyusaku Natsume, a brilliant but eccentric scientist, creates an android named Nuku Nuku. The android is built using the brain of a stray cat and is designed to protect Ryunosuke from his estranged mother, Akiko Natsume, who is the CEO of a powerful weapons manufacturing company. Akiko is determined to reclaim Ryunosuke, believing he belongs with her, and employs her company's advanced technology and resources to achieve this goal.

Nuku Nuku, despite her origins, exhibits a cheerful and nurturing personality, often acting as a surrogate mother figure to Ryunosuke. Her superhuman abilities, including enhanced strength, speed, and agility, make her a formidable protector. However, her feline instincts occasionally lead to humorous and unpredictable behavior, adding a layer of comedy to the series. The dynamic between Nuku Nuku, Ryunosuke, and Kyusaku forms the emotional core of the story, as they navigate their unconventional family life while fending off Akiko's relentless pursuit.

The series blends elements of science fiction, action, and comedy, with episodic conflicts often arising from Akiko's attempts to capture Ryunosuke using increasingly elaborate and outlandish methods. These encounters frequently escalate into chaotic battles, showcasing Nuku Nuku's combat prowess and resourcefulness. Despite the ongoing conflict, the narrative also explores themes of family, identity, and the meaning of humanity, as Nuku Nuku grapples with her dual nature as both a machine and a living being.

The characters are distinct and contribute to the series' unique tone. Ryunosuke is a typical young boy caught in the middle of his parents' feud, while Kyusaku is portrayed as a well-meaning but absent-minded inventor. Akiko, though antagonistic, is not purely villainous; her actions stem from a misguided sense of love and responsibility. Nuku Nuku herself is a standout character, embodying both the innocence of a child and the ferocity of a protector, making her a compelling and endearing protagonist.

The plot is driven by the constant tension between the Natsume family and Akiko's corporate empire, with each episode presenting new challenges and adversaries. The series maintains a lighthearted tone despite its action-packed sequences, ensuring a balance between humor and excitement. Overall, "All Purpose Cultural Cat Girl Nuku Nuku" offers a mix of heartfelt moments, comedic antics, and thrilling battles, making it a memorable entry in the anime genre.