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.
The Philippines does not share any land borders with other countries. It is surrounded by the sea and shares maritime borders with countries such as Taiwan to the north, Indonesia to the south, and Malaysia to the southwest.
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.
Haiti and the Dominican Republic share the island of Hispaniola in the Caribbean. Indonesia and Malaysia also share the island of Borneo in Southeast Asia.
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.
Haiti and the Dominican Republic share the island of Hispaniola in the Caribbean. New Guinea is shared by Papua New Guinea and Indonesia.