Tobu Railway runs the weekend winter season-only "Snow Pal 25:55" all reserved seat limited express between Asakusa (dep. 23:55) and Aizukogen Ozeguchi Station (arr. 05:33) in Fukushima Pref. for the benefit of skiers. It's a one-way only (down) service. The return is an ecs move (回送).
departing Asakusa:
Arriving Kasukabe. This is one of three intermediate station stops, the others being Kita-Senju and Shin-Koshigaya.
The return empty coaching stock move (somewhere in Tochigi?):
Tobu website info regarding this train:
http://www.tobu.co.jp/snowpal/
*interestingly, tickets/reservations can only be purchased through Tobu Travel Agency offices, by internet, or by phone. They cannot be purchased at regular train station ticket windows/TVMs.