An interesting article about “Sento” (Japanese Public Bathhouses) with its historical background. Apparently today is “Sento day” Sento = “Sen” (=1000) and “to” (=10)
https://www.nippon.com/en/views/b07302/
Considering Kumamoto is blessed with many natural hot springs, one may wonder the difference between “Sento” and “Onsen”
Found this explanation in Google;
The difference between the two may be confusing for foreigners. “Onsen” means a hot spring. At an “onsen” spot, a hot water is always taken from a natural hot spring. Most of “sento”, on the other hand, use tap water heated by boilers.
So if you are really the curious ones, the next trip you go the public bathhouses , you can try asking if the water is from natural hot springs or tap. 😃
-Olivia-