At this time of year there are alot of bugs so you had to keep the windows closed at all times. One of the reasons fpr being there was to hear the stream at night and the fresh cool air.
Staff were helpful and the place was nice. Booking the private onsen incurs an additional charge (which isn’t mentioned at the time of booking - however is on the website). The hotel is somewhat remote, so best to arrange to have dinner and breakfast there as the town is a little far away - ok if you have a car though.