In December 2024, four people lived on Aoshima, a rock of 0.49 square kilometres in the Seto Inland Sea. About eighty cats lived there with them. That ratio, roughly twenty cats per human, is the thing that made Japan’s cat islands a fixture of travel listicles and phone wallpapers for a decade. It is also, if you look at the dates rather than the photographs, the shape of a village dying and a cat colony dying slightly more slowly behind it.
The internet version of these islands is a paradise. The actual version is a set of depopulated fishing settlements where the cats arrived for a job, kept doing it long after the job stopped existing, and are now the last thing keeping the ferry timetable alive. Both are true. Only one is interesting.
Table of Contents
- Where Japan’s Cat Islands Are, and How Many There Actually Are
- Aoshima: Four Residents, Eighty Cats, One Ferry
- Tashirojima and the Shrine Built for a Dead Cat
- Silk, Sardines, and the Decree That Freed Japan’s Cats
- Japan’s Cat Islands Are Not All the Same
- Sterilization Solved One Problem and Started Another
- What Tourism Did to Japan’s Cat Islands
- Frequently Asked Questions
Where Japan’s Cat Islands Are, and How Many There Actually Are
There is no official register. “Cat island” is a nickname applied by visitors and travel media, not a designation with a threshold, so the count shifts depending on who is writing. The list that circulates most often runs to ten: Enoshima in Kanagawa, Okishima in Shiga, Sanagishima in Kagawa, Muzukijima in Ehime, Manabeshima in Okayama, Iwaishima in Yamaguchi, Aijima, Aishima and Genkaishima in Fukuoka, and Kadarashima in Saga. Other roundups stretch it to fifteen.
Two islands carry the reputation, at opposite ends of the country. Aoshima sits off Shikoku in the Seto Inland Sea, part of Ozu city in Ehime Prefecture. Tashirojima is in the northeast, about 15 kilometres from downtown Ishinomaki in Miyagi Prefecture. Geographically they have nothing in common. They have the same story.
Aoshima: Four Residents, Eighty Cats, One Ferry
Aoshima is 1.6 kilometres long, tops out at 90.8 metres, and has no shops, no restaurants, no cars and no vending machines. In a country where a vending machine will find you on a mountain path, that last absence tells you most of what you need to know. The ferry runs two return trips a day from Nagahama port, 35 minutes each way. Miss the afternoon boat and there is nowhere to buy dinner.
How the cats arrived
Sardine fishing built the village. Fishermen took cats aboard to deal with rats, which chewed nets and ate stores, and routinely left cats behind on the island when they sailed on. The cats stayed, ate scraps and rodents, and bred without much interference. That is the standard mechanism by which cats colonised most of the world’s coastlines. The unusual part is what happened next.
The numbers, and why they disagree
Aoshima had roughly 900 residents in 1945 and peaked at 165 households in 1960. Then the sardine fishery collapsed, the young left for the cities, and the arithmetic went one way only: about 50 people by 2013, 13 in 2018 with an average age above 75, six in 2019, five in May 2023, four in December 2024.
Cat counts are messier, and it is worth being blunt about that. Reporting from the 2015 viral wave put the population at “more than 120” cats against fewer than 20 residents, a ratio of about six to one. Yet when the mass sterilization ran in October 2018, 210 cats were caught and fixed, with an estimated ten more that evaded capture. Those two figures cannot both be careful counts of the same colony. Treat the pre-2018 numbers as tourist-eye estimates and the 2018 figure as the only real census the island ever had. By December 2024 the count was about 80, and every one of them was older than seven.
A 2023 genetic study published in the Vavilov Journal of Genetics and Breeding looked at the coat-colour alleles of the Aoshima population and found it descended from a small founder group imported around the middle of the last century for rodent control. The colony lacks mutant alleles for dilution, white spotting, tabby and ticked patterning that turn up in other Japanese cat populations, which is why the island reads as overwhelmingly ginger and tortoiseshell in every photograph anyone has ever taken there. Pretty, and also a genetic bottleneck rendered in fur. Roughly a third of the surviving cats have been reported as ill, with the illnesses linked to decades of inbreeding. Our explainer on the science behind familiar cat behaviour covers the same animals from the other side.
Tashirojima and the Shrine Built for a Dead Cat
Tashirojima is bigger and better organised: 3.14 square kilometres, 11.5 kilometres of coastline, and a 40-minute ferry on the Ajishima Line. Around 1,000 people lived there in the 1950s. By 2015 that was down to roughly 80, with 83 percent classified as elderly, and the cats numbered in the several hundreds. Recent counts put the colony near 100 and residents under 70, though again the cat figures depend on who is counting.
The island’s history is stranger than Aoshima’s. It was a penal colony during the Edo period. In the early Meiji era it turned to silk production, and cats were shipped in from the mainland for one specific reason: mice eat silkworms. A cat on a silk island was not a pet or a mascot. It was equipment.
Neko-jinja, and reading cats for weather
Fixed-net fishing became common after the Edo period, and fishers from other areas would stay overnight on the island. The cats worked the inns for scraps, the fishers grew fond of them, and then something more useful happened: the fishers started reading cat behaviour as a forecast. How a cat sat, when it groomed, where it settled, all of it got folded into predictions about weather and the size of the catch. Whether the cats were any good at it is beside the point. In a pre-radio fishing economy, any extra signal was worth having.
At the centre of the island is Neko-jinja, a shrine to a cat, which is genuinely unusual even in a country comfortable with shrines to almost everything. The origin story is small and grim. While fishers were collecting rocks for their fixed nets, a stray rock fell and killed one of the cats. They buried it and enshrined it on the spot. No transformation, no vengeance, no supernatural bargain, just guilt turned into architecture. Set that against the history of black cat superstitions in Europe, where centuries went into deciding cats were suspicious.
Dogs are not allowed on Tashirojima, because the cats are the point. The 2011 Tohoku tsunami destroyed the harbour, caused ground subsidence, and scattered the colony inland. Only part of it came back, and at least 80 cats were captured and vaccinated against parvovirus in the aftermath. The harbour was rebuilt by 2015. The school had already closed in 1989. What remains on the tourism side is Manga Island, a set of cat-shaped lodges built in 2000, and an annual 6 and 10 kilometre marathon first run in 2007.
Silk, Sardines, and the Decree That Freed Japan’s Cats
The reason Japan ended up with cat islands rather than, say, cat valleys is economic. Two industries that mattered enormously, sericulture and coastal fishing, both had a rodent problem, and both sat in places that were hard to reach.
The policy history is direct about this. In the Heian period, cats were luxury animals kept by the nobility, frequently on leashes, which is a good way to have a beautiful pet and no pest control. In 1602 an imperial representative in Kyoto decreed that cats be allowed to run free, explicitly so they could deal with the rats threatening the city and the silk industry. In 1685 the shogun Tokugawa Tsunayoshi, in his edicts on compassion toward living things, forbade tying up cats and dogs at all.
Read those dates together and you get the founding condition for every cat island in the country: a national policy of untethered cats applied to an archipelago of small, isolated, rodent-plagued economies. The cats went out and did not come back. It is the same culture that produced wabi-sabi, an aesthetic comfortable with decay, which is either a coincidence or the most fitting detail in the whole story.
Japan’s Cat Islands Are Not All the Same
Flattening them into one destination is the standard travel-media error. They differ in ways that matter.
Sanagishima, off Tadotsu Town in Kagawa, went viral for one specific image: cats leaping across a gap in the seawall, mid-air, which the internet named “flying cats”. Muzukijima in Ehime breaks the pattern entirely because it is not a fishing island. It is covered in citrus groves, in a prefecture famous for oranges, so its cats grew up around fruit stores rather than nets. Manabeshima sits in Kasaoka City, Okayama, roughly two and a half hours from Kasaoka Station, far enough out to filter casual day-trippers. Enoshima, southwest of Tokyo, is the opposite: about four kilometres around and easily reached.
The common variable is not cats. It is depopulation. Every island on the list is a place where the working-age population left and the animals stayed. Cats did not colonise these islands. Humans decolonised them.
Sterilization Solved One Problem and Started Another
By early 2018, Aoshima’s situation had stopped being charming. A colony of two hundred-plus animals on half a square kilometre, fed irregularly by tourists and a dozen residents in their late seventies, is not stable. In February 2018 authorities announced a plan to spay and neuter every cat on the island, backed by the Aoshima Cat Protection Society. The operation ran that October.
It worked exactly as designed, which is the problem. No kittens are known to have been born on Aoshima since. The population fell from over 200 to around 80. Every remaining cat is past seven, a third are unwell, and no cohort is coming up behind them. The colony is not being managed toward sustainability. It is being wound down, humanely, on a schedule set by feline lifespan.
Nobody involved made a bad call. The alternative was uncontrolled breeding into a food supply that depends on ferry passengers remembering to bring something, in a colony already carrying decades of inbreeding. But it is worth naming what trap-neuter-return means here. On a mainland city colony, TNR stabilises a population that strays will top up anyway. On a closed island, it is a terminal diagnosis with good intentions. There is no clinic on Aoshima either, so every procedure means shipping in a vet, equipment and volunteers, at a cost that regularly outruns the available subsidy.
What Tourism Did to Japan’s Cat Islands
The 2015 boom was sudden and mostly accidental. Photographs of Aoshima’s cats swarming a visitor spread worldwide, and a village of fewer than twenty pensioners with no shop, no cafe and one small ferry became a bucket-list item. Press coverage at the time already asked whether this was a new form of tourism or a bad precedent. Ten years on, the answer looks like both.
The good: attention brought food, veterinary funding and enough political weight to get the 2018 sterilization organised at all. The bad: the cats came to depend on it. Reporting from the period described Aoshima’s colony subsisting substantially on rice balls, energy bars and potatoes handed over by day-trippers, which is a diet no vet would sign off on and a supply chain that runs on the weather. Feeding is now restricted to designated areas.
Tashirojima handled it better, mostly by accident of scale: larger, closer to a real city, reachable from Tokyo via Sendai, with actual lodging. Aoshima had none of that, and as of 2024 more of it has been closed off to visitors because the infrastructure is deteriorating faster than four residents can maintain it. There is a version of this story where the internet saved an island. There is a more accurate version where the internet arrived, took the photographs, and left the place exactly as depopulated as it found it. For the opposite policy, see Longyearbyen, where cats are banned outright. For the unhurried travel these islands reward, our guide to slow living beats any itinerary.
Frequently Asked Questions
How many cat islands does Japan have?
There is no official list. The most cited count is ten, including Aoshima, Tashirojima, Enoshima, Okishima, Sanagishima, Muzukijima, Manabeshima, Iwaishima, Aishima and Genkaishima. Some guides push it to fifteen by adding islands where cats are plentiful rather than dominant.
Can you stay overnight on Aoshima?
Not practically. The island has no hotel, no restaurant, no shop and no vending machines. The former elementary school, closed in March 1979, was converted into visitor accommodation, but the standard visit is a day trip on one of the two daily ferries from Nagahama port. Bring your own water and food.
Why are the cats on Aoshima mostly ginger and tortoiseshell?
Genetics. A 2023 study in the Vavilov Journal of Genetics and Breeding found the colony descends from a small founder group brought in around the mid-twentieth century for rodent control, and lacks several coat-colour alleles common in other Japanese cat populations, including those for dilution, white spotting, tabby and ticked patterning.
Why is there a shrine to a cat on Tashirojima?
Neko-jinja was built after a rock fell and killed a cat while fishers were gathering stones for fixed nets. They buried the animal and enshrined it on the spot. Cats had already been part of island life since the Meiji-era silk industry, when they were imported to kill the mice that ate silkworms.
Are Japan’s cat islands going to disappear?
Aoshima almost certainly. With four residents as of December 2024, around 80 cats all older than seven, and no births since the 2018 sterilization, both populations are on a countdown. Tashirojima has more residents, better transport and real visitor infrastructure, but it is on the same curve more slowly.
The Ending Nobody Wants to Photograph
Cat islands are usually filed under wholesome. They are actually a record of Japanese rural depopulation with better photo opportunities. The cats came for rats and silkworms, stayed because nobody stopped them, and outlasted the industries that hired them. Now they are outlasting the villages too. Aoshima will likely end with the last elderly cat and the last elderly resident, in some order, and the ferry will stop. That is not a tragedy exactly. It is what happens when a place runs out of people and the animals are the last ones holding the lease.
More on the animals than the geography: why cats knock things off tables, and forest bathing in Japan, both good company on a slow ferry.
🐾 Visit the Pudgy Cat Shop for prints and cat-approved goodies, or find our illustrated books on Amazon.
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