Tashirojima (田代島?) is a small island in Ishinomaki City, Miyagi Prefecture, Japan. It lies in the Pacific Ocean off the Oshika Peninsula, to the west of Ajishima. It is an inhabited island, although the population is quite small (around 100 people, down from around 1000 people in the 1950s). It has become known as "Cat Island" due to the large stray cat population that thrives as a result of the local belief that feeding cats will bring wealth and good fortune. The cat population is now larger than the human population on the island. (A 2009 article in Sankei News says that there are no pet dogs and it is basically prohibited to bring dogs onto the island.)
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Since 83% of the population is classified as elderly, the island's villages have been designated as a "terminal villages" (限界集落) which means that with 50% or more of the population being over 65 years of age, the survival of the villages is threatened. The majority of the people who live on the island are involved either in fishing or hospitality.
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There is a small cat shrine (neko jinja (猫神社?)) in the middle of the island, roughly situated between the two villages. In the past, the islanders raised silkworms for silk, and cats were kept in order to keep the mouse population down (because mice are a natural predator of silkworms). Fixed-net fishing was popular on the island after the Edo Period and fishermen from other areas would come and stay on the island overnight. The cats would go to the inns where the fishermen were staying and beg for scraps. Over time, the fishermen developed a fondness for the cats and would observe the cats closely, interpreting their actions as predictions of the weather and fish patterns. One day, when the fishermen were collecting rocks to use with the fixed-nets, a stray rock fell and killed one of the cats. The fishermen, feeling sorry for the loss of the cat, buried it and enshrined it at this location on the island.
There are at least ten cat shrines in Miyagi Prefecture. There are also 51 stone monuments in the shape of cats, which is an unusually high number compared to the other prefectures. In particular, these shrines and monuments are concentrated in the southern area of the island, overlapping with the regions where silkworms were raised.
As you may have noticed from the initial description, Tashirojima is located in the area affected by the massive earthquake. Fortunately everyone's all right--the island wasn't razed by the tsunami--but supplies are running short and donations are being requested.
An extensive blog post on Tashirojima is here.