Shishijima can only be reached by ferry both from Amakusa and Kagoshima's Shoura island, which is bridged over to mainland Kyushu via Nagashima Island. It's a scenic (if somewhat overpriced) cruise of about 30 minutes either way.
The island is quite mountainous, with steep hills descending into the sea in rocky capes. There are two small villages and a scattering of other houses all in the coves where a minimal amount of flat land exists (total population is 1050 people). Thus, the circuit road is quite hilly, climbing over spurs and descending into small valleys.
Some of the spurs have newly constructed viewpoints reached by short trails from the road - an effort to attract tourists? The views are great.
On the eastern side, the road finally descends to the coastline for stretches, with very scenic views of Amakusa and mainland Kyushu beyond the Yatsushiro Sound.
Laver-like seaweed is farmed along the seashore using net-like structures placed so that they are alternately covered and uncovered by the tide, for optimum growth of the algae.
Someone made a playful swing hanging from the branches of a banyan tree along the seashore.
Overall, a romantic outing combined with a great workout!