which pass is suitable for me?

Hello there,

I recommend using a 7 day JR Pass for your itinerary. You can cover the following with it:

Tokyo - Nagano (return, for Snow Monkey park) ¥ 8,400
Nagano - Nozowa ¥ 710
Nozawa - Matsumoto ¥ 3,810
Matsumoto - Tokyo (with a stop at Fuji) ¥ 10,430
Tokyo - Nikko ¥ 5,780
Nikko - Sendai ¥ 9,270
Sendai - Yokohama ¥ 11,940

For a total of ¥ 50,340 or ¥ 21,240 in savings, as the 7 day JR Pass is ¥ 29,100.

So you can make very good savings using the JR Pass.

Hope this helps,
Daniel