"Etotama ~Nyan-Kyaku Banrai~" is a fantasy-comedy anime that blends traditional Chinese zodiac mythology with modern-day Japan. The story centers on Takeru Amato, a college student living a mundane life, who encounters a strange cat-like creature named Chū-tan. Chū-tan is revealed to be one of the Etotama, celestial beings representing the twelve animals of the Chinese zodiac. Each Etotama possesses unique powers and is tasked with maintaining balance in the world. However, Chū-tan is an incomplete Etotama, lacking the ability to transform into her zodiac form, the Cat, due to a historical exclusion from the zodiac cycle.

To achieve her goal of becoming a full-fledged Etotama, Chū-tan must gather "Tama," a form of spiritual energy, by forming bonds with humans. Takeru becomes her primary source of Tama, and their partnership sets off a series of comedic and action-packed events. The narrative unfolds as Chū-tan and Takeru navigate challenges posed by other Etotama, who test Chū-tan's worthiness to join the zodiac. These trials often escalate into chaotic battles, blending slapstick humor with supernatural elements.

The series introduces a colorful cast of characters, each representing a zodiac animal, such as the confident Rat (Nya-tan), the stoic Ox (Ushii), and the mischievous Monkey (Saru-tan). Their interactions with Chū-tan and Takeru drive much of the plot, highlighting themes of perseverance, friendship, and self-discovery. As the story progresses, Chū-tan's determination to earn her place among the zodiac becomes a central focus, culminating in a climactic confrontation that tests her resolve and the strength of her bonds with Takeru and the other Etotama.

The anime balances its comedic tone with moments of emotional depth, particularly in exploring Chū-tan's insecurities and her desire for acceptance. The integration of Chinese zodiac lore with contemporary settings and vibrant character dynamics creates a unique narrative that appeals to fans of both fantasy and comedy genres.