The easiest way to arrive there is from Tokyo to Omiya Station, and there you take the New Shuttle which is the following train, and its first stop is in the museum:
That is in the walk from the station to the museum entrance, there are many funny places for kids:
Once inside the museum, there is a dissected steam locomotive that you can see at concrete hours in motion and understand how it functions:
Now some real material in the main exhibition:
There are also many scale models in this main hall of the museum:
That's the view of the main exhibition from the terrace of the first floor:
Also in the first floor there is an overview of the history of the Japanese railways through scale models and preserved objects:
Finally, the huge HO scale layout:
I meet there the person in charge of the maintenance of the trains and had a nice talk with him:
Visit the museum if you are in Tokyo, don't miss it!!!!