Snow in Late December near Tokyo

Hi! I want to see a lot of snow when i go to japan this last wk of december. Not just a few random piles of snow, but those in postcards and travel advertisements haha like the beautiful photos of Shirakawa-go in winter.

What daytrips from tokyo are best?
Are the Juhyo Ice Monsters in Zao Mountain already formed in late december?
Is Shirakawago already beautiful by then? Or do i have to go as far north as Akita?

Depends on the season. Last year (2015) was a very warm December and there was not much good snow until January.

Shirakawago isn't very close to Tokyo. How about Gala Yuzawa in Niigata Prefecture? http://www.japan-guide.com/e/e7690.html

As already mentioned, in December 2015 there wasn't much snow anywhere near Tokyo. You have to go far north if you want guaranteed pile of snow. The closest place i can think of is Nagano, particularly the ski resorts there, or if you don't want to ski you can visit jigokudani park with the bathing monkey, there should be plenty of snow at the end of December.