The Wikipedia article for Yonaguni, Okinawa states:
Yonaguni is much closer to the capital of Taiwan (Taipei) at approximately 100 mi (160 km) than its own capital(Tokyo), which is about 1,250 mi (2,000 km) away. Due to this it is attempting to establish closer relations with Taiwan, including attempting to set up easier access to and from cities in Taiwan, with irregular service to Hualien already established.
But I can't seem to find whether this is a flight, ferry, or doesn't actually refer to transport at all.
Until now I knew there was a ferry between Taiwan and Okinawa that ceased operations in 2008, but this information was added to Wikipedia at the end of 2009.
Google just throws up lots of fishing/clickbait that don't contain useful information, unfortunately.
So is there an irregular transportation connection, and what details do we know?