I lived and taught in Japan for several years. I also did my doctoral research in Japan. I still have a lot of friends in Japan. And I took my family (husband & 2 daughters) on a 3 week Japan vacation back in 2018. Been an HGVC member since 1999. I actually plotted the location of all the HGVC Japan timeshares. I believe almost all are located in the countryside (which could also include the seaside). They are ryokans with onsen. Ryokans are a type of traditional Japanese inn and the onsen is a like a hot springs public bath located indoors, outdoors or both. For Japanese, the whole point of traveling to an ryokan is to be at the ryokan and onsen and relax. Everyone who goes to Japan should spend at least one night in a Ryokan with an onsen.
That said, I believe most Americans who travel to Japan, including myself, want to spend the majority of time in the cities. We got a three week Japan rail pass, or JR pass, which is an excellent bargain. We stayed in and or traveled to Tokyo, Kyoto, Osaka, Kobe, Himeji, Hiroshima and Beppu.
We stayed exclusively at AirB&Bs, which were incredible deals. In Kyoto we stayed in a three story modern house for 7 nights for $800 total. It was a 7 minute walk from the train station. The neighbors were awesome. The rest of stays were in condos. Tokyo was the most expensive but still not bad.
I made sure that wherever we stayed it was no more than a 10 minute walk to a JR line rail station.
Also, double check. Ryokans often charge by the person not by the room. And if I’m correct, I think HGVC points might be by person not by room. Staying in a ryokan via HGVC was going to be really expensive. If you calculate the amount of points it would take to stay there.
oh, and the Ryokan I stayed in, a Japanese friend found it for me. I booked it myself. It wasn’t an HGVC ryokan.
Let me know if there is anything else I can help you with.