We drove almost 1000km on a motorhome in Japan. Various people who would like to come and travel in Japan by RVs seem to have big concerns about driving on the left side of the road or not being able to read the signs. Also concerns about getting lost & not being able to communicate with the locals seems as a point of concern, however, everything is very well organized with roads and signage in excellent conditions. In addition, as Japan is experiencing a big boom in tourism, the Japanese government has made significant efforts to make everything accessible in English. Also these days, most rental companies offer bilingual navigations to ease getting around. Of course, Google and other services are fully bilingual.
Japanese drivers typically keep a calm manner and i.e. merging lane maneuvers are done coolly with very little squeezing in the last moment. Once you merge, a double hazard light blink is the typical thank you. Even if one makes a mistake it is extremely unusual to hear honking. I often joke that you really don’t need a horn in Japan!
Other factors that make driving here easy are the low speed limits (50 km/h on local roads & between 80 and 100 km/h on highways) plus the fact that 99.9% of all passenger cars and RVs have automatic transmissions.
While traveling, there are plenty of parking facilities in and out the cities. Once you get into the countryside, you will be able to find an abundance of camping spots and also “Auto Camp Sites” which welcome tent and RV visitors. Furthermore, as Japan is basically crime free, a night or two on the beautiful beaches along one of the coasts will make for great memories.