Just in case you hadn't seen yet:
you can now buy canned Four Roses and IW Harper bourbon "highballs" in Japan. I haven't been tempted to try either one yet, though I'm sure there will come a time. It's part of an overall whisky'n'soda in a can trend here.
You can also get a Four Roses "highball" with your whopper at Burger King in Japan. I have had this, and it does make the dining experience slightly more enjoyable. It's pretty weak though.
Just thought I'd relay this info.