LactoseJoe comments

I do not think tailgating causes road rage here in Japan.

It's both. I've had driver's tailgate me out of nowhere which has enraged me. Take this for example: driving on a single lane mountain road between Nagano and Hakuba whilst following six or more cars in severe rain, a Fiat 500 approaches my rear and hangs on to my bumper (within approx. 2m). There is nowhere to pass with a constant stream of oncoming traffic and even if the driver were to pass, could he have taken six vehicles under these conditions, absolutely not. I pulled over and let him pass as it was just too dangerous. At a set of lights up ahead I had the intention of getting out and confronting him but hesitated and the lights went green.

I have many more examples of this kind of behaviour where the tailgating is the initiator.

Unfortunately, Japanese drivers seem all too confident to ride your tail, yet lack any confidence to confront the victim's dissatisfaction when it occurs. And tbh, that, as the person confronting the perpetrator is the most frustrating thing, seeing the sad middle-aged man awkwardly stare in any direction besides yours as you attempt to reconcile why he was riding your bumper.

Though there are some incredibly polite people on the roads here, there seem to be quite a few that are unable to use the roads safely at all, I mean, these guys are doing things we did in Europe over 10-15 years ago; I've seen babies crawling on dashboards, countless people on their phones, and hell, I saw a kei car fall on its side from clipping the outside kerb whilst trying to spin a quick u-turn. What exactly do they do in the driver's license examination?

You can't win against them, you will be facing down with an inifinite number of terrible drivers, you have to just just try and relieve yourself of the situation. It will never end for as long as Japan oppresses its citizens via its own culture and employs such rudimentary driver training.