Kikai Island, or Kikaijima, is a small island located in the Amami Islands, just to the east of Amami Oshima. While it is a part of Kagoshima, due to a long and varied history of being conquered, culturally Kikai is a blend of Okinawa, Amami, and Kagoshima traditions.
Kikai only has two direct connections to the outside world, Kagoshima and Amami Oshima. Going to Kikai from anywhere will require you to go through one of those two places.
A one-way ticket from Kagoshima will cost you approximately ¥24300. A round-trip ticket is approximately ¥44200 total, or about ¥22100 each way, making it slightly cheaper, but still pretty expensive. Purchases made far in advance on the Japanese JAL website may allow you to obtain a ticket for as little as ¥16400 each way. The journey takes about 1 hour and 15 minutes.
Bouncing out of Amami is possible, though no cheaper. A normal flight from Amami Oshima will cost ¥9500 for a one-way ticket and as little as ¥6400 if purchased far enough in advance. It's still fairly expensive if you consider that flight is only 10 minutes.
Kikai only has one ferry route which is operated by A"LINE Ferry. This ferry runs from Kagoshima to Kikai, Amami Oshima (Naze and Koniya), Tokunoshima (Hetono), and sometimes Okinoerabujima (China) and does not continue to Okinawa unlike the other ferries from Kagoshima. The journey from Kagoshima takes about 12 hours and runs overnight. A one-way ticket from Kagoshima costs ¥9800. There is no ferry service on Sundays and Mondays.
Make no mistakes, Kikai is small. The coastal road surrounding the island can be walked in 6 to 8 hours depending on your pace, meaning that getting to any specific point on the island will probably take no more than 2 or 3 hours on foot. This of course assumes that you have a specific point that you are trying to get to. Most of Kikai outside of the main town is endless sugar cane fields.
If you need to get somewhere specific and don't feel like walking for hours (especially in the summer heat), there is a bus service (air-conditioned) operated by A-Line Ferry.
The fare is ¥300 to anywhere on the island.
There are 3 bus routes on the island. Two of them, 北本線 (north line) and 南本線 (south line) follow the coast road clockwise and counter-clockwise respectively. The third 中央線 (center line) runs into the island interior, and is somewhat less useful unless you're looking for a way to get up into the mountain(s).
The bus is populated mostly by 70- to 90-year-old women in varying states of decay either going to, or returning from, the hospital. If you're looking for a place to hear some of the island's endangered language, the bus is a great place to do it.
Primary administrative division