Yes. The My Name is Legion run.

And they're also involved with Proteus, which makes them a fun toy to play with now, not that I've been at a loss to use them.

I pick a AAA, but only because I just haven't gotten around to fleshing it out yet with threads that exist. With the others, I'm just lazy and have no reason not to use them.

Well, being an AAA by no means guarantees that it has assests all around the world.
As the novatech case proved, it's sometimes a matter of owning the seat of a CC founder corp (in this case, JRJ). If someone owns a company that owns a CC seat, then even if the core company has been stripped to bare bones and look like a pop and mom company, he's still entitled to have a seat in the CC and be a AAA.

That's why, IMHO, some of the new AAA don't see much play. It's difficult for people to take those newcomers like Cross or Wuxing as real equals to the older AAA. What saves Novatech is that it's a third of former Fuchi, once the 2nd most powerful AAA. But the 2 others look like opportunist corpos, but I can't buy the idea that they built an international network of assests overnight once they got the AAA status... especially because getting the AAA tag sometimes is just politics (the way Wuxing got in for example). As you said, for Cross, it seems most of their assets are in Quebec. And maybe the truth is not that different from that feeling.

See, that is precisely why I like using them. The players can't weasel out any hidden agendas or be burdened with OOC player knowledge, simply because Shiawase is so generic. All you can really say about them is "well, they are Japanese". It makes for a great AAA corp to work with, because they are at least average in all areas, and the players won't secretly be thinking "Lofwyr's out to get me" or "Here come the Blood Mages"

Shiawase is one of my favorites, as well, but I don't really think of them as generic. They are in competition for the top slot in Bioengineering, Nanotech and Atomic Power, udesputedly top dogs in the service industry, and the MIFD is mensioned in just about every product involving Shadowrunners.

I think they're underused because Shiawase does mostly resonable buiseness. I mean, they don't have any "crazy 6th world gimic". Seriously, would anybody run with S-K if Lofwyr was instead a board of directors? As exiting as the world of natual reasources, heavy industry, and phone companies are, I doubt S-K would get much playtime without the good dragon. And Aztechnology? They invest primarily in CONSUMER GOODS! How many players would be proud to infiltrate a Pyramid to get their hands on the newest top-of-the-line prototype toaster? Add in human sacrifice and Blood Spirits, and suddenly it feals like your character's doing something.

Shiawase doesn't get respect because they settle problems with lawyers and analysts and general cleverness (not unlike an actual corporation) instead of Blood Mage or Great Dragon crazyness or overengineered trap laden guaranteed death automated killing everything zero-zone everywhere there's a company presense.

Shiawase is subtler than that. They don't need Hachiman to tear you apart, or Red Sams to hunt you down--they can just have the MIFD keep an ear to the ground and send someone to your home to talk things over with you before anyone has to resort to violence or acts of more questionable legality.

I once had my players infiltrate an Aztechnology facility to get "valuable data", which turned out to be a new recipe for Fruit Salad. Later, in another Shadowrun, the players had to infiltrate an Aztechnology "NuFruit Inc." facility. *grin*

When I run Aztechnology, I severely downplay the blood magic and play up the fact that the majority of their business is making food products and consumer goods.

There are story elements in the Shadowrun metaplot that involve Shiawase (the Shiawase Decision, the weird Ryoi Shiawase ghost channeling, the above Psychotrope reference... was that Shiawase?), but nothing that distinctly fits into the Shiawase MO. If there is are plot hooks worth fishing (and you really have to fish deep), I would recommend doing something with either the HMHVV vaccine they are working on, or the MIFD (this is the marketing department of doom, for those unfamiliar with it... it is the Orwellian Big-Brother information-gathering juggernaut, a common theme in cyberpunk). Plus, the Fuchi acquisition gave them a lot of good legacy Fuchi plot hooks that you can use. Or you can just play them as the straight-up generic Japanacorp.

And, as it says in the "Corporate Download"

One possibility to indirectly use Shiawase with a paranoid runner group is to have the Johnson make up a Shiawase background identity. The runners check out the Johnson's skinny, find out he's allegedly Shiawase, and then assumes "oh, this is going to be a vanilla shadowrun" (since Shiawase runs tend to be rather cut-and-dried and professional). Big mistake when the (insert corporate baddie) arrives. Not that Shiawase can't be vicious on its own, but it is conventionally violent as opposed to Aztlan, S-K, Ares, MCT, etc. Just another way to make your paranoid runners even MORE paranoid.

Funny, I usually leave Yamatetsu out, for no reason I can understand since I use it regularly. Maybe because it's the smallest japanacorp.