[ChisaChi]

Do you have anywhere in particular you want to go in Nagano? Some parts will be further away than others. I'm planning to go on a day trip to Karuizawa for skiing, which seems to be in a part of Nagano that's quite close to Tokyo (about an hour away by shinkansen). Doesn't leave a whole lot of time for skiing, but should hopefully be a decent taster.

Why don't you try staying a night in Osaka if you want to go there? Will give you a bit more time to explore. Although then that cuts into the time you have in Tokyo, so its up to what you're looking for.