In Japan, you can use so many types of transportation to go national trip.
Eg. Train, Bullet train, plain, walk, swim…
For people who want to save money but not time, I recommend to use night bus.
[Reference : Willer Express ]
It will take you to major and minor cities in Japan.
It departs at night and arrives in the morning of next day.
For example, return ticket for Tokyo and Kyoto is 6,100 yen.
It is way cheaper than bullet train. Bullet train normally cost more than 20,000 yen for return way.
Willer Express