Japan stands on the result of volcanic activity basically. It brings many earthquakes but also brings benefits. One of the best thing is Onsen.
We have so many onsens everywhere in Japan and we love this culture so much. You can even find one in the middle of mountain.
We don't have so good ski bars like Europe but you can enjoy apres schi in onsen. It's the acme of winter activity.
It's all about keeping clean the bath and public area. Even some Japanese can't behave properly but these are etiquettes of taking a public bath.
*Bring a small towel with you so that you can wipe yourself before you go back to locker room.
*Wash yourself first and rinse throughly before you get into the bath
*Tie your hair up if you have long hair and do not put your towel in the water. Again the point is keeping the water clean as much as possible.
*Normally the temperature of the water is around 40 - 42 degrees centigrade but you may feel it's too hot. Please take time to adjust your body. Some people really love hot water and don't like others add cold water. If you feel the water is extremely hot though you tried to get used to it, let's get someone around involved to get agreement to add water, so that you can avoid a trouble. In this case don't forget to stop water when you finish.
*It's not considered good to leave your stuff at a shower booth. Put your stuff on a shelf if any or somewhere out of the way so that people can use the shower booth.