湯の児温泉 海と夕やけ
(ゆのこおんせん うみとゆうやけ)
Uses natural hot spring water
381. Yunoko Umi to Yuyake, Minamata, Kumamoto Visited for higaeri for 500 yen. Higaeri listed as 14:00 to 18:00. They issue Toreco cards for this onsen. Photos from the internet roughly match — I was there in daylight but everything looks very similar. Indoor bath with clear water, temperature around 40. Breathing is good. Before the stairs from the first floor indoor bath to the second floor outdoor bath, there's a box with disposable shorts (but no large sizes), listed as mandatory since if you stand up fully in the outdoor bath you'll be visible from the park. Though if you slide into the water from the edge directly, everything will be fine. Small outdoor bath with a nice view, clear water, temperature around 43. The hassle with the disposable shorts is a bit off-putting, but otherwise it's decent.