It is really quite simple.

The whole thing about the left hand side of the road for those not used to it should not be a problem if you recall that you gauge where you are vis a vis the lane divider in the US by keeping the front left wheel stable in relation to what you see slightly ahead of the car. Works exactly the same way here. Riding a motorcycle on the left is much easier though as you actually see the lane dividers.

In general the Japanese drivers will treat the road with a great deal of respect for its inherent dangers, but they much like American drivers do so to excess and end up driving with too much trepidation which also can be quite dangerous.

My advice is do not expect the quality of driving you would see in England or Germany, but instead expect the poor road skills seen in the US and drive accordingly defensively.