10 days to cover Tokyo, Osaka and Hokkaido

Dear all,
Planning to travel on 9/10 Nov back on 18/19 Nov 2012. Couple with 3 kids. Kuala Lumpur - Osaka (2 nights) ok? Wanted to go Universal Studio, Mount Fuji
Osaka - Sapporo (3 nights) enough?
Sapporo - Tokyo spend 3 or 4 nights in Tokyo to cover Disney Land, Disney Sea, etc..

First Trip for d kids visiting Japan. Pls assist me on the itinerary. Many Thx.

I recommend: Osaka - (air) - Sapporo - (air) - Tokyo with side trip to Mount Fuji. It is going to be a busy trip, but it is possible.

It's possible but, IMHO, isn't worth the effort unless you can get wonderful airfare between the cities.
http://www.japan-guide.com/e/e2364.html

Kansai-Sapporo and Sapporo-Narita are fortunately among the most competitive routes in all of Japan, with one way fares starting from around 4000 yen.

Look out for fares by Peach, Jetstar Japan and Skymark, in particular.