Like the US and Scotland, Japan has suffered its share of closed distilleries, including some that are deeply missed. As with Brora, Port Ellen and Stitzel-Weller, the whiskies from these distilleries are both highly treasured and highly priced.
Hanyu shut down in 2000 but under the stewardship of Ichiro Akuto, scion of the distillery owning family, there has been a steady stream of Hanyu whisky released under the Ichiro's Malt label. I became a Hanyu convert a few years ago after sampling the 15 and 20 year old expressions and subsequently hunted down as much of the popular, single barrel playing card series as I could find. The best of these were among the best malts I've ever tasted (if you see the pictured 20 year old Jack of Diamonds, grab it!). The more recent releases, which tend to be younger, have left me less impressed. The flavor profiles very from massively sherried to rather straightforward and malty.
Due to its scarcity, it's unlikely that we will ever see any Hanyu whisky in the US, but in 2008, Ichiro started his own distillery, Chichibu, which is now bottling some of its very young whiskey, and he has also done some Chichibu/Hanyu vattings. Perhaps, eventually, we will get some Chichibu.
Like Hanyu, the Karuizawa Distillery closed at the dawn of the twenty-first century. Also like Hanyu, even though the distillery is gone, new expressions continue to be bottled by those who own the old stock which, in this case, is the London based Number One Drinks Company. For this reason, it may be easier to find rare Karuizawas in Europe than in Japan.
The Number One Drinks vintage series of malts, which has gotten rave reviews in Europe, tend to be huge sherry monsters coveted by those who love their Glenfarclas and GlenDronach, but other expressions vary. The standard 17 year old for the Japanese market, for instance, is much lighter on the sherry, less bold and complex than some of the vintage malts but very drinkable nonetheless.
As with Hanyu, it's unlikely that we will see any Karuizawa in the US, but we can always dream. (UPDATE: Check the comments; it looks like at least one retailer is going to prove me wrong on this, and I've never been so happy to be wrong).