Ok, first an apology if this is repeating a well-known truth about Japan. For everyone else, here is a primer on Japanese toilets.
There is a missing link for Japanese toilets
Strange as it may seem, in Japan you either find the traditional squat toilet or highly-technological, all-singing, all-dancing bidet/toilet. There are no plain toilets in Japan and you can quote me on that.
Even urinals aren’t a simple affair. The separate porcelain units invariably have sensor for ands-free operation. Even my mother-in-law has a Toto sensor urinal next to her Toto Washlet.
At the Oriental Hotel in Kobe (the historical hotel at 25 Kyōmachi, Chūō-ku, not the Kobe Merikan Oriental Hotel) we had a Toto Washlet with special remote.
The control unit can be daunting. Fortunately one merely had to close the lid to flush.
The control allows you to change the position, strength, frequency and direction of a stream of warm water to the bottom or bits area. (If you missed my warning about themes, then you don’t understand what people use a toilet for.) By default a fan draws air away from the room and the seat is heated. It is my theory, perhaps alone in the world, that a warm bum area encourages stool production.
But perhaps I’m talking out of my arse.