While Japan has an extensive and easy-to-use public transportation system, there may be times when you'd like to get out in the countryside with your own car. How hard is it really to drive in Japan? As an American who got a Japanese drivers license and a car in Japan, I feel its not too hard if you keep a few things in mind.
Drive on the Left
Pretty straightforward - you sit on the right side of the car and drive on the left side of the road.
Pick a Small Car
Japanese roads are small. Parking spaces are small. Do yourself a favor and pick the smallest car that will fit yourself, your travel companions, and your luggage.
Pay to Park Anywhere
Coming from America where you always look for free or cheap street parking, this one came as a bit of a shock to me. In cities and towns, you must pay to park in a lot. Free street parking does not exist. In the countryside, most parking lots don't charge, but you still need to park in a lot rather than on the street.
Stop at all Rail Crossings
Every. Single. One.
No Turn on Red
As there are many more pedestrians and cyclist in Japan than America, you cannot turn left at a red light.
Take it Slow
Speed limits are overall pretty slow in Japan - even on the highway. And as the Japanese are generally not agressive drivers, take it slow and enjoy the scenery as you drive in Japan!