Anybody heard of this one? 9 strings!

One of the other players on this local TV show we were on had a strange-looking 9-string guitar, 6 machines on the right of the headstock, 3 on the left. My first guess was three extra bass strings, but when I talked to the guy after his set, it turned out the three lows were normal E, A, D, and the other six were in pairs, also in standard. That is, each pair were tuned to the same note, G,B,E. I suppose you could make them harmonic if you wanted, but this guy was just using them for mandolin/banjo type sounds, while doing bass runs on the bottom. It was an Alvarez Yairi, which he says is a handmade premium brand. I have heard of Alvarez before, but not Yairi. Yairi is apparently the original luthier in Japan. The player of this guitar told me he bought it about 30 years ago. Anyway, it was a beautiful and great-sounding instrument, and I have never seen one before tonight. Have you?