The phrase most likely refers to a specific travel or bathing experience at one of Japan's historic hot springs known for its " Gensenfuro " (源泉風呂), or natural source bath.
Gensenfuro 28 is still there. You can find it if you drive past the last vending machine and walk until the road becomes roots. But if you step in, and the water hums a low F-sharp... -2011- Gensenfuro 28
: This could simply be the name of a document or file, possibly related to a project, report, or publication titled "Gensenfuro 28," with "2011" indicating the year it was created or published. "-2011- Gensenfuro 28" The phrase most likely refers