There are two kinds of toilets in Japan*. There is the ultra-modern, super-powered, western-style version with buttons for two types of sprays of controllable intensities and another one that makes a flushing sound for the modest. (I tried this one. It plays the recorded sound of a toilet flushing until you push the "stop" button**.) And then there's the other type, which is a ditch with a splashguard.
Most public bathrooms offer the visitor a choice: sit or stand. (or squat, or whatever you're supposed to do. Never quite figured that one out.) Which is all well and good, unless there's a line. And if you have any experience with public ladies' rooms, you know there is always a line. Which makes the wait kind of tense, because you don't know what you're going to get. Which door will open when you get to the front? Will it be the safety of modern familiarity, or will it be an experience in traditional Japanese culture that you could have done very well without, thank you very much? And if you lose the toss, then what? It's a bathroom line, you can't not go in. Do you step aside and let the lady behind you take the stall, and hope for better luck on the next throw of the bathroom dice, thus announcing to everyone your toilet preferences? Or do you affect a look of unconcerned calm and stride on in and do your best?
Fortunately, I was never faced with the last question, because my door choice came up lucky each time. (Apparently, in Japan even Fate is polite.) However, I did end up using the "traditional" once, at the park on our first day, and it was not uneventful. Not in the actual use-- I'll spare you the details, but I managed to figure it out. But when I went to flush, I noticed a red button on the wall next to me. The Japanese seem to love buttons (and, really, who doesn't), so I thought "Aha, the flush!" and pushed it.
Did you know that sometimes they put alarms in bathroom stalls? Alarms that you can't turn off by pushing the button again, or anything else in the immediate vicinity? Alarms that make very loud, very alarm-like noises intended to alert anyone within fifty yards that someone has pushed the alarm button in the bathroom?
In situations like this, I find it best to locate the actual flush (handle on the tank), wash one's hands and walk briskly away.
* That I know of.
**Which should serve as sufficient proof that pranks are not common in Japan, since any public toilet here with that feature would have had it running continuously for the last ten years, thanks to kids.