nekomata,
in the setsuwa collection Kokon Chomonjū, in the story "Kankyō Hōin (観教法印)", an old cat raised in a villa on a mountain precipice held a secret treasure, a protective sword, in its mouth and ran away. People chased the cat, but it disguised itself. In the aforementioned Tsurezuregusa, aside from nekomata that conceal themselves in the mountains, there are descriptions of pet cats that grow old, transform, and eat and abduct people.[3]
Since the Edo period, it has become generally believed that domestic cats turn into nekomata as they grow old, and mountainous nekomata have come to be interpreted as cats that have run away to live in the mountains. As a result, throughout Japan, a folk belief developed that cats should not be kept for long periods.[1]
In the "Ansai Zuihitsu (安斎随筆)" the courtier Sadatake Ise stated, "A cat that is several years of age will come to have two tails, and become the yōkai called nekomata." The mid-Edo period scholar Arai Hakuseki stated, "Old cats become 'nekomata' and bewilder people." and indicated that at that time it was common to believe that cats become nekomata. Even the Edo-period Kawaraban reported this strange phenomenon.[2]
