Upvote:3
I recently read you could go by ferry directly from Tokyo to somewhere in Hokkaido (somewhere near Sapporo). It takes quite some time (something around 18h), but if you're ok with sleeping on a tatami mat in a big room with other people (apparently mostly truckers) it's probably a lot cheaper than trains (Β₯8,500 off season, Β₯11,000 peak season).
The person describing the travel wasn't too pleased with his journey, though. It all depends on your standards. And of course to tour around Hokkaido you'd still have to take trains and buses.
Have you considered the JR Pass? If you travel a lot it will most probably be worth it.
Upvote:5
Take a look at Japan's many low-cost carriers!
From Tokyo:
From Osaka:
Hitchhiking is generally a surprisingly viable alternative, but not in winter, and the sheer distance to Hokkaido (~1200 km from Tokyo to Sapporo) means it's a multi-day venture.