mapleg

Tohouku is where you want to be.

http://www.japan-guide.com/list/e1102.html

I suggest this rail pass. Will get you from Narita to wherever in the region you want to be and it is flexible...any 5 out of 14 days.

https://www.jreast.co.jp/e/eastpass_t/

and
http://www.japan-guide.com/e/e2361_tohoku.html

Or, you could even consider this if you want to go as far as Hokkaido. Although priced similarly to a 7 day nationwide pass, you can use it 6 out of 14 days which can be very handy when you want to stop and "smell the roses" in various places.

http://www.japan-guide.com/e/e2361_southhokkaido.html