Question about a folk song


So this might be a strange request, but I'm looking for any information anyone might have on a folk tune. I found this piece based on Okinawan folk songs called Teachi-tearu by Hirokazu Fukushima, and the program notes say it uses themes from Teachi-tearu and Tinsagu nu Hana. I can find plenty of info on the latter song, but I'm coming up short on the first one so I figured I'd take a shot and see if anyone here could tell me anything.

Song link: https://youtu.be/zidLuATTiDE?si=5ZU2Fxgnw5s5AE6w

by sweet_condensed_rage