Let me tell you about Onsen

Onsen bathing is fantastic. I think everyone is aware of the general concept of Japanese bathing.
You have public onsen where everyone bathes together (genders separated) in a communal facility and that is what we have been enjoying so far.  This hotel has 2 private onsen. It's like a bathroom but bigger and is more than large enough for a couple. The general layout between the 2 types is the same. There is an entry room where you undress, with cubicles for clothes. Mirrors, hairdryers, moisturizer etc are usually provided. Then, in a large onsen you go into a large steam filled room which usually also has 2 or more large pools of very and very very hot mineral water. There is usually also an outside pool and in our last hotel it was artfully arranged with large boulders. There you sit and look out onto the snow & woods. At this boutique hotel, the onsen looks out onto a garden/woods but the windows don't open.  The bath/pool here is approx 2m x 1.20m and faced in black marble or granite. 
So... on entering the 'bath' room, large or small, you sit on little stools and wash yourself thoroughly before you get into the bath/pool. There are no namby pamby rules about how long you stay in - it's up to you.
If you want to wash your hair, you either do it before or after the hot bath but if after, then you do not wet your hair in the pool.
I am absolutely sold on the onsen idea. In western baths you recline and it hunches or rounds your shoulders and is not good for your back/neck. The Japanese style, while shallow compared to a swimming pool, is deep enough to sit upright and the water comes to over your shoulders.  Fabulous.  Mind you they don't have to heat the water.  New Zealand hot spring facilities could do an awful lot better. I seriously doubt any Japanese would even consider getting in one, except of course the posh one at Rotorua.
Obviously there is no way I could take a camera into a public onsen. Even if you timed it so no one else was there, the steam would wreck it. But here I was able to leave the doors open and photograph before it got cold so the condensation was minimal ...and I used my phone.
ps: I may not manage a post tomorrow. We have a final image review in the morning before our flight at 11am & we are not likely to get to our hotel until 5ish.

The washing area with little stools and sluicing bowls

The onsen (bath) itself

The view onto the garden