Deep in an ancient forest where cats can use magic, a fire-breathing dragon was hatched and raised by a mother cat as one of her own. The dragon grew up alongside his feline siblings, learning their ways and developing a deep bond with them. As years passed and the original cats eventually left him behind due to their shorter lifespans, the dragon grew into a powerful guardian of the forest, vowing to protect the generations of cats that followed. The cats affectionately call him Uncle Wing, while humans, who know little of his gentle nature, fear him and refer to him as the Cat Dragon.

The story takes a darker turn when the dragon witnesses cats being killed by humans for their fur. Enraged by this cruelty, he takes revenge, killing the adventurers responsible for the deaths. This act deepens his hatred of humanity, and he becomes a feared creature who keeps his distance from the human world. However, a fateful encounter with another cat reminds him of his past and softens his heart, eventually allowing him to develop a cat-like form.

The central character is Nekoryu, the dragon voiced by Takehito Koyasu, whose identity is caught between his draconic nature and his upbringing as a cat. Mama-nyan, voiced by Kikuko Inoue, is the mother cat who raised him and remains a formative presence in his life. Other important cats include Kurobane, a black cat who goes on adventures with a human prince, and Shirotae, a white cat who teaches magic to a lazy girl living in an orphanage. The series also features human characters such as a king who forms a peace treaty with the dragon to protect cats, and Annerossa, a young magician who accidentally summons Mama-nyan and develops a lasting bond with her.

The narrative unfolds in an episodic or anthology format, following the various cats of the forest as they grow up, leave the nest, and seek their own territories. Some choose to live alongside humans, leading to adventures and friendships that slowly bridge the gap between the dragon and the human world. A prince embarks on an adventure with his black cat master, a lazy girl discovers magic through a white cat mentor, and one cat even becomes the poster figure for the adventurers guild. Throughout these interconnected stories, the dragon remains in the forest, teaching new generations of kittens how to hunt and watching over his ever-expanding feline family. Over time, he gradually warms to the presence of humans, challenging his long-held fears and changing his perspective on the world beyond the forest. The series balances cozy, slice-of-life moments with gentle adventure, exploring themes of found family, identity, and the unlikely bonds that can form between different species.