Ryukyuan Languages

I fell into the youtube rabbit hole and stumbled upon some videos uploaded by user wadoku2008 and wadoku2012. In the video below, Byron Fija, a native of Okinawa born to an American father and Okinawan mother, discusses the different languages of the Ryukyu Islands in the Uchinaaguchi language. There are some Japanese words interspersed and the grammar seems very Japanese, but the sound and intonation of it is very different. There are glottal stops in strange places (coming at it from a Japanese language point of view) and sometimes it almost sounds like Korean. I don't know much about the historical roots of languages of the islands of Japan, but this has made me more interested in getting a deeper understanding of it.