by liberal japonicus
One thing that the Japanese are exceedingly good at is appropriating things from other cultures and making them their own. Latest acquisition? Halloween! Those pictures are not the best, this page has better photos, though it is for a party, so you may think that this is more staged than real, so this link, with a movie and 300+ pics, from Tokyo downtown last year gives you an idea. The general pattern is that this is taken up in Tokyo and within a few years, gets picked up in places further out, of which this is no exception.
This article gives a bit more background.
I hope this might give folks not here a taste of how Japan (much like any dominant culture) acts as a blender, taking whatever bits and pieces that happen to catch interest, tossing them in, and making the results unrecognizable. If there are any pics which seem inexplicable, drop a link in the comments and I'll try to explain.