Male Restroom Etiquette.
The following is presented as a public service to all men. Women may watch it, but they won't understand it. (They tend to go to the loo in pairs. I suspect the etiquette differs substantially.) Warning: this tape runs a little long at over 9 minutes but it is certainly worthwhile and may save your life.
The トイレ (toire) politeness situation in Japan is similar but there are vast differences too. Men are still supposed to remain silent when going about their business yet I've noticed that the rules are broken under the following circumstances.
1. When peeing in a club's restroom with only 2 urinals, it's okay to talk provided it is only extremely innocuous chitchat about the music or the voluptuous women.
2. A gaijin shouldn't speak to a local under any circumstance. This is not a rule, just common sense.
3. When a local strikes up a conversation with a gaijin, just politely mmhmmm and nod your head. Once outside of the washroom, you may continue the conversation if you wish.
4. UNDER NO CIRCUMSTANCE SHOULD YOUR EYES WANDER. Pay attention to the business at hand. Eyes Front!
When at an onsen or public bathhouse, circumstances change somewhat. Because you are essentially naked with naught but a small towel to cover yourself, try and keep your eyes to yourself. Unfortunately, for some odd reason, older salarymen tend to lose their inhibitions when they are naked and find that since they have a captive audience, it is the perfect opportunity to practice their English. They tend to get braver and will chat about anything. Personally, I prefer to carry on conversations when fully (or even partially) clothed. The same cannot be said for my Japanese brethren. (Another word of advice: yet again, don't let your eyes wander. What you see...or not see, may surprise you.)
If any of you have some good toilet stories, let me know. I'll post them here. For example, I have one rather largely-endowed female gaijin friend who often gets her upper torso fondled while in the onsen, not out of any come-on, but out of curiosity.
In the immortal words of Homer Simpson when visiting a commode in Japan:
Toilet: Welcome. I am honored to accept your waste.
(toilet goes into an elaborate water show in its bowl)
Homer: (gasps) They're years ahead of us!