The Wild, Wild West
After the end of World War II, Yonaguni's tiny fishing port of Kubura became a hub of black marketeers shipping goods mostly stolen from Japan to Taiwan in exchange for food and other scarce commodities. At the boom's peak the island's population had swelled to 20,000, including 38 bars and 200 hostesses. Alas, with the post-war normalization of economic conditions the black market vanished and Yonaguni returned to its quiet ways.
Yonaguni is among the remotest inhabited spots of Japan and getting there is both inconvenient and expensive, although this may change if connections to Taiwan improve. Both flights and ferries may be cancelled at short notice if the weather is bad particularly around typhoon season, so allow some buffer in your plans.
By plane
Expanded in 1999 to allow jets to land, tiny Yonaguni Airport OGN fields 1-2 flights daily from Ishigaki on Japan Transocean Air and Ryukyu Air Commuter 30 minutes, ¥10000/17000 one-way/return, and RAC flights 3 times a week from Naha.
In addition, TransAsia Airways (http://www.tna.com.tw/) operates irregular charter flights from Hualien, Taiwan 40 min, around ¥5000 one-way. Check with the airline or call 0980-87-2241 in Yonaguni for more information.
By ship
Fukuyama Kaiun ç¦å±±æµ·é, tel. 0980-87-2555, runs boats from Ishigaki on Wednesdays and Saturdays, with return trips on Mondays and Thursdays, always departing at 10 AM. The trip takes four hours on a good day and costs ¥3460/6580 one-way/return; note that most of the journey is across the open sea and people prone to seasickness may wish to steer clear. A cargo boat also offers an irregular unscheduled service to Naha.
Star Cruisesã (http://www.starcruises.com/) operates irregular cruises in the summer season only from Keelung Taiwan to Yonaguni. As of 2009, they're running again after a pause of a few years.