OKINAWA ISLAND

I was here: March and April 2013.
Number of days: 12.
Recommended number of days: between 5 and a week.
My score: 4/5.

The largest of the islands that conform Okinawa prefecture and whose name it carries, is also the most complete and accessible, and although it is not most recommendable if what we are looking for are indescribable tropical beaches (the best ones are on the islands further south), it will not disappoint anyone:

Known worldwide among fans of martial arts for being the cradle of Karate, this island attracts thousands of practitioners a year, who come to train from all corners of the world with the greatest and venerable masters of the art.
Its beaches are of undeniable beauty, especially those of its nearby Kerama islands, such as Tokashiki and Zamami. You can also go hiking or cycling through its jungle forests.
Okinawa aquarium is one of the best in the world. It is known for housing the largest water tank that exists, in where among hundreds of other fish of all sizes, 3 whale sharks live. It is really impressive and worth visiting even if you have seen other large aquariums before.

American military aside, foreigners barely arrive here. Despite being one of the main tourist destinations in the country for locals, the vast majority of tourists do not spend more than two weeks in Japan, mostly dedicated to Tokyo and Kyoto and their surroundings. It is true that its main attraction, the beaches, despite being magnificent, are similar to those of other tropical destinations, while the cities of Honshu are unique, but all those who have enough time in the country, would do well in keep an eye on this prefecture so different and special.