"Nansensu Monogatari - Daiichi-hen - Sarugashima" is an anime series that blends surreal humor and absurdist storytelling. The narrative centers on a group of characters who find themselves on the mysterious Sarugashima, an island inhabited by anthropomorphic monkeys. The monkeys, who possess human-like intelligence and behavior, govern the island with their own peculiar customs and societal structures. The human characters, often bewildered by the island's bizarre logic, navigate a series of comedic and nonsensical situations as they interact with the monkeys and attempt to understand their world.

The protagonist, a young man named Ken, serves as the audience's entry point into the strange world of Sarugashima. Ken is accompanied by a small group of companions, each with distinct personalities that contrast with the absurdity of their surroundings. Their interactions with the monkeys, who often speak in riddles or engage in illogical behavior, drive much of the humor and plot progression. The monkeys themselves are portrayed as both comical and enigmatic, with their leader, a self-proclaimed king, embodying the island's chaotic and unpredictable nature.

The plot unfolds through a series of episodic adventures, with each episode presenting a new absurd scenario or challenge for the characters to overcome. These scenarios often involve satirical takes on human society, as the monkeys mimic human customs in exaggerated and nonsensical ways. Themes of identity, societal norms, and the nature of logic are explored through the interactions between the humans and monkeys, though the series maintains a lighthearted and comedic tone throughout.

The animation style complements the surreal nature of the story, with exaggerated character designs and vibrant, whimsical backgrounds that enhance the absurdity of Sarugashima. The dialogue is sharp and witty, filled with wordplay and comedic timing that adds to the series' charm. While the narrative lacks a traditional overarching plot, the episodic structure allows for a wide range of comedic and imaginative scenarios, making each episode a self-contained exploration of the island's peculiarities.

Overall, "Nansensu Monogatari - Daiichi-hen - Sarugashima" is a unique and entertaining series that thrives on its absurd humor and imaginative world-building. Its blend of surreal comedy and social satire offers a distinctive viewing experience, appealing to fans of unconventional storytelling and offbeat humor.