Driving in Japan is not difficult.
Comparatively,Japanese driver's have a good manner.
But,the big cities as Tokyo or Osaka is very crowded.
"JYUTAI"(traffic-jam) occur Everyday.
Sometimes,It takes 3hours to drive through "JYUTAI" about 20km.
if you would like to go the suburbs or rural destrict,recommend to drive.
Japan Biker F.A.Q. This page is for Biker,very understandable.