After this preliminary washing, you climb into the tub for a good, long soak. The Japanese like their bath hot, but you can adjust the temperature to your liking with water from the tap. When you are warmed up to the bone, you get out of the tub and wash your entire body clean. Rinse off all the soap suds by splashing yourself with plenty of water and then slip back into the tub for a second soak. Some people condense this ritual into two processes.
Many persons use the same tub water for soaking.
Therefore, it is a matter of courtesy for those who go in first to keep the water clean. If you should soap or scrub your body inside the tub, it is going to cause trouble for the room maid or the bathroom attendant. And you may be regarded as a barbarian who doesn't know how to take a bath in a civilized way - the same thing they must be saying in Paris, London or Los Angeles about that Japanese country hick.