"Okawari-Boy Starzan S" is a comedic anime series that blends science fiction and adventure elements. The story centers around Starzan, a young boy raised by gorillas in the jungle, who possesses superhuman strength and agility. His peaceful life is disrupted when he encounters a group of humans, including a scientist named Dr. Peacock and his daughter, Mimi. The narrative unfolds as Starzan is thrust into a series of misadventures, often involving Dr. Peacock's eccentric inventions and the pursuit of a mysterious energy source known as the "Cosmo Stone."

The Cosmo Stone becomes a central plot device, attracting the attention of various factions, including a greedy businessman named Mr. Gold and his bumbling henchmen. Starzan, with his innate sense of justice and naivety, becomes entangled in the conflict, striving to protect the jungle and its inhabitants from exploitation. Alongside Mimi and Dr. Peacock, Starzan navigates a mix of slapstick humor, action-packed sequences, and lighthearted moments, often highlighting the contrast between his primitive upbringing and the complexities of human society.

The series features a recurring cast of characters, including Starzan's gorilla family, who provide comedic relief and occasional assistance. Mimi serves as a grounding presence, often explaining human customs to Starzan, while Dr. Peacock's inventions frequently malfunction, leading to chaotic yet humorous outcomes. The episodic structure of the series allows for a variety of self-contained adventures, ranging from thwarting Mr. Gold's schemes to encountering strange creatures and exploring the jungle's hidden secrets.

"Okawari-Boy Starzan S" maintains a lighthearted tone throughout, with its humor derived from Starzan's fish-out-of-water experiences and the exaggerated antics of the supporting cast. The narrative emphasizes themes of friendship, environmental preservation, and the clash between nature and technology, all while delivering a steady stream of comedic and action-oriented entertainment.