The very charming Nakagusuku location of Yaka Soba occupies a very old traditional Okinawan kawara (ceramic roof tile) house that was almost a spitting clone to my Grandmother's in layout. I did feel at first the relatively new tenants (I've heard the place had been in business for only a few years now) could've been there more as a gimmick for tourists, but it turned out Yaka Soba was far from being a tourist haven. At least not yet. ;)
Shown below is the medium sized Nankotsu (cartilage) Soba at only 400-Yen (~$5) which was still a nice fill for me. The soup had the stronger Hon-Katsuo bonito flavor which seems to be in vogue these days, but I hear places like previous Hamaya Soba with their subtle broths still top the local "best okinawa soba" charts.
Trend or not I extremely liked the punchy bonito flavors (you can see a bag of the shavings on the counter if you click on the second to last image below). The biggest surprise was the choice of flat or thin (somen-like) noodles. I chose flat of course and remember its notably fresh taste that made an impression on me which also added to the great experience.
The thick cut Takuan is self service AYCE from the nearby communal fridge as were the Benishoga red pickled ginger. And BTW, the nicely flavored meaty cartilage pieces were out of this world tender.
I went for the smaller bowl of soba because the pork lover that I am wanted to try the katsu curry that I heard good things about. Got the half order to share which was a good thing because it also still turned out to be a decent portion. The thinner pork katsu was indeed perfectly crispy/tender and great while the Japanese curry had a more mild curry powder based retro/nostalgic flavor, but one with tons of umami from sweet vegetables.
The place is hard to find but very well worth the visit if you can find it. Sorry, I was driven to the place so I can't help much! :P