Suggest sidetrip between Kusatsu-Sendai Feb

Hi all.
Im not sure how to put this.
I need help on suggestions on where i should side visit between Kusatsu and Sendai in mid Feb 2017

I will meet up with friends and spend Feb 10-14(noon) in Kusatsu for snowboarding, then will meet up with another friend in Sendai/Zao(snowboarding) on 20th Feb onwards.
Between 14th Eve till 19, im thinking to spend time to check out nature/landscapes, old structures and towns(like Shirakawa) in between these 2 cities maybe for snow photography .
Would need recommendation on interesting places.

I will have the 5days flexi Tohoku pass (for Sendai-Yamagata, and Sendai-Tokyo, and still have 3day usage to spare) and mix with bus rides.

Looking fwd to the suggestions.
Thanks

Oh, forgot to note that i'm not considering Shirakawago as
1.i have been there in summer few yrs back
2.the last bus in winter is somewhat still too early to snap nightscapes

I have been to AizuWakamatsu, but never manage to make way to the old street Ouchijuku. Is it worth the effort to just go there as its slightly branched out a lil too much from Kusatsu-Sendai path?

I have never been to Gunma and Tochigi areas.

I suggest Tadami - Aizu region.
Personally I have once taken the line, when I was very young, long long time ago, and it was in summer and I did not visit any towns except Aizu-Wakamatsu. So, this is just a suggestion I have imagined at which I would like to visit the region in your place.

First, read this good article on this site.
Following the Tadami Line in Oku Aizu
http://www.japan-guide.com/blog/raina/161011.html

About Tadami Line:
https://en.wikipedia.org/wiki/Tadami_Line

Timetables (10 January to 31 March 2017: from Tadami to Aizu-Wakamatsu):
http://www.city.aizuwakamatsu.fukushima.jp/docs/2013070900048/files/H2...
(The right one is for direction from Tadami to Aizu-Wakamatsu (bus and train).

From Koide station to Tadami station:
There seems to be three trains.
http://www.city.aizuwakamatsu.fukushima.jp/docs/2013070900048/files/H2...

They say there are good skiing grounds in the region. In your place, I would stay one or two nights in those skiing areas.

How about doing a loop north of Kusatsu to Sendai? There's a few snow festivals on that week.

Yokote Kamakura Festival on Feb 15 and 16: http://www.japan-guide.com/e/e3690.html

Lake Towada Winter Story till Feb 26: http://towadako.or.jp/event-info/

I visited Geibikei Gorge this Feb and it was stunning in winter: http://www.japan-guide.com/e/e5006.html

wow..
thanks ... and Mon for the suggestions. They are relevant to my interest.
The Tadami line looks fascinating, but i think i will have a hard time to find budget accommodations along the way(too rural), seeking best spot to snap pictures, and slow train +limited timetable.

Yokote and Towadako seems doable , so i will look further into this

Just found out that JR bus do not run in winter to Towadako :/

Im still looking fwd to recommendations.

Note:
I have been to AizuWakamatsu bus loop coverage, Hiraizumi shrines, Kitakami village, Aomori, Hirosaki, Niigata

Just in case anyone is interested to check out Towadako Winter Story, theres special JR bus service scheduled on Feb 11-12 and 18-19 2017 from Hachinohe
http://www.jrbustohoku.co.jp/route/detail/?PID=1&RID=30

source:
https://towada-city.blogspot.my/2016/12/lake-towada-winter-story-2017....