"All Purpose Cultural Cat Girl Nuku Nuku" centers around the misadventures of Nuku Nuku, a highly advanced android created by the brilliant but eccentric scientist Ryunosuke Natsume. Nuku Nuku's body is powered by the brain of a stray cat, giving her a unique blend of feline instincts and superhuman abilities. She is designed to serve as a protector and caretaker for Ryunosuke's son, Kyusaku Natsume, who is caught in the middle of his parents' tumultuous relationship.

The series unfolds as a comedic sci-fi action story, with Nuku Nuku frequently clashing with Mishima Heavy Industries, a powerful corporation led by Ryunosuke's estranged wife, Akiko. Akiko, a ruthless businesswoman, seeks to reclaim Nuku Nuku for her own purposes, viewing the android as a valuable asset. This leads to a series of escalating confrontations, with Nuku Nuku using her extraordinary strength, agility, and combat skills to fend off Mishima's forces while trying to maintain a semblance of normalcy in her daily life.

Kyusaku, a middle school student, often finds himself caught between his parents' conflicting agendas. Despite the chaos, he forms a close bond with Nuku Nuku, who becomes a surrogate mother figure to him. Nuku Nuku's childlike innocence and feline quirks add a layer of humor and charm to the series, as she navigates human emotions and societal norms while fulfilling her role as a protector.

The narrative blends slapstick comedy, action-packed sequences, and moments of heartfelt family drama. Nuku Nuku's dual nature as both a powerful machine and a naive, cat-like being creates a dynamic character who is both endearing and formidable. The series explores themes of family, identity, and the ethical implications of advanced technology, all while maintaining a lighthearted and entertaining tone. The interactions between Nuku Nuku, Kyusaku, Ryunosuke, and Akiko drive the story forward, creating a balance of humor, action, and emotional depth.