Originally Posted by
bmwe92fan
3) Definitely take the Shinkansen at least once -- we use it all the time and love it as it is so much more relaxing (to us of course). Flying domestically in Japan is quite easy -- but don't forget the expense of getting from the airport to the city -- some are quite far away and taxis are not cheap.
4) Rental cars are pretty easy as well -- just make sure you have an international drivers license -- or a license that is accepted for rentals in Japan. Just a note -- parking in major cities can be expensive and sometimes difficult to find...
+ 3 & 4 - If you are considering long distance driving cost performance, also check the highway tolls and gas costs.
https://www.japan-guide.com/e/e2354.html has a chart for approximate tolls and there's ways to lookup current tolls based on route. Take the highway and do not opt for local roads to save on tolls. The added stress & increased drive duration is not a good trade off unless you have sufficient time, no need to accommodate kid bladders, and need to be frugal. There are youtube videos showing Tokyo - Osaka route via freeway but in short, the toll roads are well maintained and there's highway rest stops (aka roadside stations) with gas stations, electric car chargers, restrooms and food options. Some are themed quite nicely and fun for kids.