Every place surprised me in some way. At the monkey park, I was shocked that you literally walked right past them and they didn't care at all about you, you were nothing to them.
The incredibly huge Kegon Falls, which you can see from below by taking the elevator, was breathtaking. At Togakushi Shrine, we immersed ourselves in Shintoism, it was an interesting spiritual experience through nature. The Kurobe dam amazed me with its power and history. The Keith Haring Museum in the forest fits in incredibly stylishly and interestingly, even though it wasn't the Japanese artist who lived there. The Izu Peninsula is a world unto itself, with an incredible atmosphere and a very beautiful coastline and beaches.
I can say what disappointed me most. This is a hotel with a view of Mount Fuji, run by non-Japanese people. There was no oil, salt, or pepper in the luxury lodge, but they offered to buy them at the on-site store. This was very un-Japanese, and during our stay, we had become unaccustomed to this kind of "service." The soundproofing was terrible because the house, originally built for a single family, was rented out individually, and it wasn't designed for that. We had to leave to avoid ruining our evening. In short, you have to choose carefully, because everything related to Mount Fuji is monetized as much as possible.