None. Japan is a series of islands. The nearest countries are South Korea and Russia.
Borneo
Indonesia, Malaysia, and Brunei share the island of Borneo.
No One, The Galapagos Islands are some 600 odd miles (900 odd kms) from the nearest land.
Jamaica is an island which does not share borders with any other countries. The three closest islands to Jamaica are Cuba, Haiti, and the Cayman Islands (which are a territorial possession of the United Kingdom).
They are all primarily Muslim countries.
Malaysia, East Timor and Papua new Guinea.
Australia does not have a land border with any country. However, it does have official borders / maritime boundary treaties with other countries, as specific water borders are officially laid out. Australia has a sea border with New Zealand, Papua New Guinea, the Solomon Islands, East Timor and Indonesia. There is even an officially delineated border agreement between Australia and the French government, given that New Caledonia is French territory.
Three of the countries near to Indonesia share borders with the country. These countries are Malaysia, Papua New Guenna, and East Timor. Other countries that are close include Australia, Singapore, and the Philippines.
Three countries share the island of Borneo: Malaysia, Indonesia, and Brunei.
Thailand, Indonesia, and Brunei are neighboring countries of Malaysia. They all share borders with Malaysia.
Australia is only bordered by water. It is a free standing continent consisting of only one nation. So, the answer is no, it does not border any international cities.However:The mainland continent of Australia does share official maritime borders with other countries. It shares these borders with Papua New Guinea, East Timor, New Zealand, Indonesia, the Solomon Islands and New Caledonia (France).In addition, its offshore territories share maritime borders. These include borders with Papua New Guinea, East Timor, New Zealand, Indonesia, the Solomon Islands, New Caledonia and the Kerguelen Islands (France).The Australian Antarctic Territory shares land territory borders with New Zealand, Norway and France.