Well, card shows don't happen that often in Japan. To start with, Japanese people don't consume as much of anything. Most box busters are the stores themselves, or collectors who then "donate" their extras to the stores to keep clutter away. So there aren't as many dealers with product to move. And while older product can be popular, the desire to get the latest and greatest is even more important here in Japan than in America - vintage is a tiny subset of the collecting population. I'd gather that most collectors here are player or team collectors who don't want to bust open a ton of packs. This changes the kinds of cards you might find at a show. I wonder if any collectors actually throw away trading cards here - a definite possibility given the lack of concern for condition for most base and inexpensive insert cards, even in the recent past.
I'm sure I miss some shows but there's only one I know of in Tokyo this year - it happened last weekend, I attended, and you'll hear about that later. There seems to be a group of dealers who travel around central Japan (Osaka and Nagoya mainly) that holds a show in those areas about once a month. I happened to be in Osaka during their late April/early May show there, and again in Nagoya at the end of May for that show. What you see here is some of my findings.
All these cards came from the Osaka show. What I found there, in a fairly small meeting room, was about 15 dealers with a decent variety of cards. Some had high prices, and some had great prices. The Calbee dealer was a very pleasant surprise, but I also found a bunch of single inserts at 50% or more off usual prices. There were also plenty of foreign issues available - MLB, NBA, and NFL mainly - plus soccer, which is pretty big out here. Additionally, I found a few tables with boxes.
Several of the dealers at the Osaka show traveled the hour or so by bullet train to the Nagoya show (or vice versa) leaving me with basically the same selection. I think I spent a couple bucks on something, but I doubt it. The room was smaller and there were fewer dealers. If I hadn't been to the Osaka show, I would have been fairly happy at Nagoya.
One thing to point out is the kind of dealers you should expect to find at Japanese card shows. Because average collectors probably don't keep tons of cards they don't want in their tiny apartments, mostly full-time sellers set up at card shows. This means card stores set up at card shows - they bring their latest product and a couple mixed boxes and plop their stuff on a table. But this also means that prices aren't great. Card stores can bring their stuff back to the shop and let it sit for daily buyers. Compare this to US card show dealers - usually they're collectors making money on the side or only part-time (show-only) sellers, looking to clear stuff fairly cheaply to keep room for next month's new cards, and with a low overhead as well.
So, Japanese card shows have the same basic selection like you'd find at American shows - new singles and some random recent old inserts and star players, plus boxes - but at higher prices/less of a discount than you'd expect in America. Remember, Japan is the land where a 5% discount is a big deal!
That said, I'm happy to have gone to a card show in Japan, and hope to have more opportunities to check out other shows around the country (and here in the Tokyo area)!