"Koryu no Mimi" is a fantasy anime series set in a world where humans coexist with mystical beings known as the Koryu, who possess unique abilities tied to their animal-like features. The story centers on Mimi, a young Koryu girl with rabbit-like ears and a tail, who is ostracized by both humans and other Koryu due to her inability to manifest a traditional power. Despite her perceived weakness, Mimi harbors a rare and ancient ability to communicate with the spirits of nature, a gift long forgotten by her kind.

The narrative begins with Mimi living in a secluded village, where she is treated as an outcast. Her life takes a dramatic turn when a mysterious force begins corrupting the natural balance of the world, causing spirits to become hostile and threatening the existence of both humans and Koryu. A human scholar named Haruto, who studies Koryu history, discovers Mimi’s unique connection to the spirits and convinces her to join him on a journey to uncover the source of the corruption. Together, they travel across diverse landscapes, encountering other Koryu tribes, each with their own customs and abilities, as well as human factions with conflicting agendas.

As the journey progresses, Mimi learns to embrace her identity and the significance of her power. The duo uncovers a forgotten prophecy that foretells the rise of a "Spirit Whisperer" who can restore harmony between the natural and spiritual realms. Along the way, they face numerous challenges, including battles with corrupted spirits, political intrigue among human leaders, and internal conflicts within Koryu communities. Key characters include Ruka, a fierce Koryu warrior with feline traits who initially distrusts Mimi but becomes a loyal ally, and Sora, a human noble with a hidden connection to the ancient spirits.

The series explores themes of coexistence, identity, and the consequences of disrupting natural order. Mimi’s growth from a timid outcast to a confident leader forms the emotional core of the story, while the evolving dynamics between humans and Koryu highlight the complexities of their shared world. The plot builds toward a climactic confrontation with the entity responsible for the corruption, revealing deeper truths about the origins of the Koryu and their intertwined fate with humanity. Through its blend of adventure, mythology, and character-driven storytelling, "Koryu no Mimi" presents a richly layered narrative that balances action and introspection.