You can go surprisingly far on a single train leaving from Tokyo Station

[gmat]

You can go surprisingly far on a single train leaving from Tokyo Station. Includes using the Shinkaqnsen, though.

https://soranews24.com/2019/02/20/you-can-go-surprisingly-far-on-a-single-train-leaving-from-tokyo-station/

 

Grant

[Kiha66]

I'd like to see one in the JNR era.  I feel with Blue trains the country would actually be much more connected, since much more of Kyushu and Hokkaido would have been reachable without requiring a change.