What an awesome place! Stayed there at the recommendation of a Japanese friend. It's great to experience a traditional Japanese hotel for a few days. You sleep on the mats in your room, and you can order a dinner to be served in the room. The food is excellent, try their traditional multi-course dinner, it's a bit expensive but totally worth it! It looks like the most of the guests are Japanese, but stuff goes out of their way to make foreign visitors welcome. Most of them speak decent English. Also, try the onsen - the experience sounds a bit weird at first, but it's really amazing!
It turns out that John Lennon and Yoko Ono visited this place in 1977, if you ask, they will show you their autograph.