This lovely collection of rocky pools is not bathable within a few hours of high tide, so you'll need to check the tide tables before heading out. If it's bathable, this is one of Yakushima's gems -- hot water, konyoku (mixed gender) baths so close to the waves that they splash you from time to time. The water is heated directly by cracks in the rock, so use caution while finding a spot lest you sit directly on a vent and torch your tush.
Look closely and you'll see mudskippers hanging out on the rocks and seaweed. These cute little fish are thought to be one of evolution's earliest creations. They spend extended time out of the water because of modified fins that allow them to cling to the rocks and crawl around much like our own ancestors did, millions of years ago.
Being konyoku, there's no privacy inside the bath so this one may not be for beginners or the particularly modest to start with. But there are no changing rooms either: you simply strip and put your clothes on a rock or the path, walk to the bath, splash yourself a few times, and ease into the water. (Women can rent, if they wish to, a thin cotton dress for modesty, but it doesn't provide much.)
The minimal privacy really doesn't matter compared to the idyllic setting. Don't let prudish attitudes get in the way here. Strip and dip, you'll be glad you did.
You'll prefer to arrive by car or taxi, but there is a bus that passes by on the main road. It's infrequently timed, however, so you'll need to be careful not to miss it.
30.2307093, 130.4834807
