Italian family wish suggestion

We are a family of four, we'll arrive in Tokyo on 14 of april. We rent a car to go to Nikko, Yudanaka, Matsumoto, Kawaguchico, Kamakura, and come back in Tokyo on 17 or 18 of april. We wish to know how much is the toll of expressways, and how is the difficult to drive. Thanks.

Differences with Italy. Driving on the left side of the road. Lower speed limits (80km/hr on expressways)

Japanese drivers and roads are safe. Do not expect drivers to go at 200km/hr like in Italy.

Note that the roads through the mountains that provide a quick (and free) connection between Nikko and Yudanaka (via Numata and Kusatsu) are closed due to winter condition until April 24. So, you will have to make a detour.

As for the tolls:

Tokyo-Nikko depends on where around Tokyo you enter the expressway. But it is about 4500 yen from central Tokyo. Or about 6000 yen from Narita via Tokyo.

You can look up the tolls for the other sections here:
http://www.driveplaza.com/dp/MapSearch

and how is the difficult to drive.

Generally easy, especially if you have a car navigation system. But driving through the expressway maze of central Tokyo can be stressful and complicated.