Deep in a forest where magic exists, a baby dragon hatches inside a cave belonging to a family of cats. The mother cat, finding the orphaned hatchling, decides to raise him as one of her own alongside her kittens. The young dragon grows up believing he is a cat, learning to hunt, play, and live by their customs. As years pass, his feline siblings age and pass away while the dragon, with his long lifespan, remains, becoming the forest's silent guardian. The cats affectionately call him Hane no Ojichan, Uncle Wings, while outsiders who glimpse him speak in hushed tones of the Cat Dragon.

For generations, the dragon protects the cats living in the forest, watching over each new litter of kittens as they grow and eventually leave to find their own territories. Some cats venture to live with humans in nearby towns and cities, forming unique bonds. A black cat becomes the partner and mentor to a young, adventurous prince, teaching him magic as they travel together. A white cat takes in a lazy girl living in an orphanage, determined to enroll her in a magic academy despite the girl's complete lack of motivation. One cat even becomes the beloved mascot of the Adventurer's Guild, observing human society from a comfortable perch.

The dragon himself, however, harbors a deep distrust of humans. He has witnessed the worst of them, having seen cats killed for their fur by cruel adventurers. His anger toward humanity simmers until a fateful encounter with a particular cat changes everything, reminding him of the family that raised him. This meeting softens his heart and grants him the ability to take on a cat-like form, allowing him to move between the world of beasts and the world of humans in ways he never could before.

Beyond the wandering cats, the forest holds other wonders. A family of cats tends a generations-old field of catnip, guarding it fiercely. An old cat named Pomporra, the longest-living cat in the forest, sets out on walks that always seem slightly different from ordinary strolls. The dragon continues teaching each new generation of kittens how to hunt, even as his own understanding of family, belonging, and what it means to protect those he loves continues to grow. Through his bond with the cats and their connections to human companions, the dragon gradually comes to see humanity not as a monolith of cruelty, but as a species as varied and complicated as the cats he calls family.