Try the below book for objectives. Looking at it will definately spur you on to improving your japanese. There's another good book called Japanese snow mountaineering with even more winter alpine type routes, but i couldn't find it on amazon. It's the same publisher/series as the below book and is number 58 in the series. Also look at the english language Hiking in Japan books, although they don't have technical routes they're still useful for general mtn info.
http://www.amazon.co.jp/gp/switch-langu ... ge=en%5FJP
Am not familiar with good winter objectives in n honshu but there's plenty to do in the n alps, tateyama, tsurugi dake, yari, hodaka etc plus yatsu ga take (nearer tokyo).
I'm unable to share a rope with you as I'm in London. Try your local town/university/college climbing clubs. There are also a few brits based in japan who sometimes post on the ukclimbing forum who you could maybe partner up with.
Good luck and have fun, Japan is a great country for climbing if you have the time to get out. Spare cash and a car also help!!