Tokyo-Nagano, one spare day in between. Tips?

Hello everyone,
I am going to Japan for the first time in about a week and I have a spare day between visiting Tokyo and Nagano city.
It'll be Sunday the 19th, where would you advice me to go? I have a JR pass, no tent. I would love to see some of nature, it is no problem if it's a bit off route, I will be spending the night there and going to Nagano city the next morning.

Also, is it easy to go into nature from Nagano city? I would love to see the mountains in my time there.

Thanks in advance! Also, any other tips are always welcome :D.

Bessho Onsen is nice, and there is a nature park there though I didnt get to it. It is a short train ride from Ueda, which is a stop or so before Nagano.

Otherwise Karuizawa would be my pick (a stop or two beforehand). From the top of the shopping street there is a great hike for a few km to a lookout at the Nagano/Gunma border, and a nice temple there as well. We stay at Tsuruya Ryokan which I think is perfect for first timers in a ryokan, and very nice.

Togakushi is a 1-hour bus ride from Nagano.
http://togakushi-21.jp/data/pamphlet_e.pdf
Nature is not very many, but I also like Obuse and Matsumoto.
http://www.japan-guide.com/e/e6000.html

How about Kamikochi:
http://www.japan-guide.com/e/e6040.html

Tokyo to Matsumotoby Limited Express, see the castle (original, not rebuilt) and Kamikochi in the Japan Alps. From Matsumoto to Nagano is just under 1-hour by Limited Express Wide View Shinano.
Use Hyperdia for times, etc.

Yes! Thanks for your replies!
I will try to visit Matsumoto castle and Kamikochi on one day and Togakushi the other. Just have to figure out how to reach Togakushi from Nagano station :).

I am also planning my trip and I came across this : Take bus number 70 or 71 from Nagano Station in direction of Togakushi.
http://www.japan-guide.com/e/e6005.html

Obuse is lovely, and is also on the way to Yudanaka Onsen.

Nozawa Onsen is also excellent if you like bathing (and skiing/mountain scenery depending on the season).