Help with traveling with JR

hi, just getting ready for my first trip to japan.

Me and my girlfriend land in Tokyo on aug 1, and planning to catch a jr pass train to Sapporo on the 2nd (about 10hours?)

After spending a few days in Sapporo, planning on heading south to Osaka, what is the most economical and wallet friendly way to do this? overnight train? or do the trip in 2 legs?

After basing ourselves in Osaka for a 3-5 days days we will head to Hiroshima for several days before returning to Tokyo then Climbing mt Fuji.

Obviously quite a bit of traveling involved but we dont mind that, but does this all seem doable with a 14 day pass?

sorry for the long post, any help will be greatly appreciated!

thanks.

95% of passengers between Tokyo and Hokkaido and between Osaka and Hokkaido take a flight.

By air is going to be fastest and cheapest. You should check out the discount airlines, such as Skymark, Peach and Jetstar, in particular.

How to travel between Tokyo and Sapporo:
http://www.japan-guide.com/e/e5306.html

How to travel between Sapporo and Osaka:
http://www.japan-guide.com/e/e5306.html?aFROM=2157_2163

More expensive than the Sapporo-Osaka route but possibly even more time-efficient would be flying from Sapporo directly to Hiroshima and then take ground transportation to return to Mount Fuji via Osaka.

Also, if you visit other areas in Hokkaido besides Sapporo, you could consider using a different airport in Hokkaido to fly into or out of.