Yes all the hard hitting topics here! Something that is also a constant amusement to me are the Japanese toilets, a very popular topic with children as well as they love to hear stories of non-Japanese people's struggles with Japanese toilets.
There has been a change since I was last in Japan, public toilets now also have the variety of features that before were only found in toilets in private homes. Previously in (the ladies' toilets at least!) the cubicles had signs on them either Japanese toilet or western toilet, with matching symbols. The Japanese toilets are the squat toilets, not like the ones found in Europe, the Japanese ones are uniquely Japanese! The western toilets are the ones you sat on.
Now the cubicles list the choices as Japanese toilet and 'shower toilet', and therein lies my amusement. What are now known as shower toilets are the ones that have extra features where water is sprayed up at the person using the toilet. In the past there was a control panel at the side of the toilet bowl and all the ones I had ever come across just had Japanese writing, which led to many an unknowing westerner thinking they were pressing a button to flush when suddenly water would come spraying at them and they would exit the toilet soaked! At least now there seems to be picture clues, and for future reference the toilet flush is always behind the bowl not next to it. This knowledge saved me from many an embarrassing visit to a Japanese home!
This was the control panel in the public toilets at Narita airport, none of these buttons flush the toilet!
This was the flush control in a different public toilet, it's a sensor flush which you can often find as well, no touching those nasty germs! This was in Tokyo so helpful English instructions added. The button at the bottom right is a call for assistance, in this case it's obvious but some are not which can also lead to public toilet embarrassment for the non-Japanese reading visitor!