(chuckle!)
No idea! What did strike me when I saw it is that this kind of handsaw is a recent import to Japan. None of the carpenters I've met in Tokyo tend to use this style of saw. My partner brought a Japanese version back to the UK a couple of years ago when I mentioned that my Dad would be interested in seeing one. He loved it! Easy to work with, cleaner cut, instantly bacame a favourite in his tool kit. And he's not the only one who thought so. We've been obliged to bring back a few more for friends and family. It's actually the most popular of the souvenirs we've brought back to Europe.

Anyway, I digress. Odaiba can take hours to see. Here are a couple of links with more information (and pictures - including the giant 'western' hand saw) at least anyone tempted to go there can make a relatively informed decision as to which areas to stick to.

http://www.japan-guide.com/e/e3008.html

http://metropolis.japantoday.com/tok...storiesinc.htm

P.S. "Japanese hand saw" in Google images will give anyone who's curious an idea about what I'm talking about. You can get them in Tokyu Hands or any hradware store. Excellent tool for anybody serious about their toolkit! (look for the one with the ball in the handle, as you saw, the ball moves creating a draft that blows the sawdust away - simple but ingenious!)