
Black Zippered DS Cases
Source: Yahoo! Japan
The more rectangular one I have add for some time, and it shows up fairly often on Yahoo Japan. The one with the flap I'd not seen before and the picture was a bit small, so I asked the seller about it (to see if it was a custom modification of the other one), and they said they bought it in the Pokemon Center. That was enough for me, and after getting it I can see it's definitely a different item.
The image on these is a cool textured vinyl.
Blue Camo Pattern DS Case (Type 1)
Source: Yahoo! Japan
This is pretty similar to the below, and both show copyright of 2007 so I'd guess they were both released about the same time. Most of the things featuring Dialga in a running pose are from 2009 or later, as he got new art for the movie that year.
Blue Camo Pattern DS Case (Type 2)
Source: Yahoo! Japan
Not much to say about this one...it's a DS case with a pretty cool design!
'Smart Pouch' DS Lite Case
Source: Toys R Us, Ikebukuro, Japan
This DS Lite case has a sort of camouflage design to it. I almost overlooked it in the store, but Callyfin pointed it out to me, and now I don't have to get it on Yahoo Japan (for much more expensive). Thanks much!
Silhouette DS Case
Source: Yahoo! Japan
I'm not really sure how to describe this one, but I thought the design on it was pretty striking.
Blue and Black DS Case
Source: Yahoo! Japan
Another Dialga DS case ;-)
10th Movie Dialga Pencil/DS Case
Source: Yahoo! Japan
A nifty zippered Dialga case. This was one of my very first Dialga DS cases, I have quite a few now!
Blue DS Case
Source: Yahoo! Japan
This one much more snugly fits a DS Lite.

Hard Cover for DS Lite
Source: Pokemon Center (Hamamatsuchou, Japan)
A hard plastic cover for a DS Lite. I was pleased to find that these were still in stock by the time I got to Japan!

Hard Cover for DS Lite (black)
Source: eBay
A different design of the above case~
Game Traveler (3 versions) and Deluxe Game Traveler (by R.D.S. Enterprises)
Source: jedi_amara of pkmncollectors, Target (US Retail), eBay
The small horizontal one in front here is the standard American version, but I've never seen the larger two for sale in stores here. Jedi_amara in Australia kindly picked those two up for me! The small vertical one was a more recent eBay find.
Gold Silhouette DS Game Case
Source: Yahoo! Japan
I don't know a lot of other Dialga collectors to discuss rare items with, so I usually figure that if I'm seeing an item on YJ for the first time in 2 years of searching, it's either new or very rare. This one I think is just rare, as it's dated 2006, and I've never seen one anywhere. Holds 4 DS games!

DS Game Case
Source: PlayAsia.com
A small hard plastic game case to hold and protect a single DS game. I've got a couple of these!
DS Game Case (Gachapon Version)
Source: Yahoo! Japan
This tiny case (barely bigger than a DS cartridge) holds quite a few games. I have hard enough of a time keeping track of my games when they're in bigger cases, so I haven't been using this.
Burger King Trading Card Case Source: eBay
This is from an American Pokemon Promotion (in either late 2008 or early 2009, I can't remember which) at Burger King. I actually had this one for a while but had forgotten to add it on the site, and a kind visitor pointed it out to me. Thanks!
Dialga TCG Deck Boxes
Source: Hardrock-Pokemon, eBay
These are plastic Japanese cases to keep your TCG deck in. I've opened the one on the left, but couldn't bear to take the Spear Pillar one out of its original packaging.
The backs of these are quite different, and you can see them here.
Ultra-Pro Diamond and Pearl (01) Series Mini-Binder
Source: Toys R Us
One of the mini-binders featuring the art from the TCG packs that stores 4 cards per page.
TCG
Tournament Dialga Silhouette Card Sleeves
Source: Yahoo! Japan
Supposedly you had to win something (I don't know what) at some TCG tournament to win just 5 of these sleeves, which means you'd need to win 12 times to have enough for a full deck. Some sellers will try and sell you 5 sleeves at a time for what you'd hope to pay for a full deck, so be careful when buying sleeves from this series!
Great Encounters Ultra-Pro Binder
Source: eBay
I bought this on eBay thinking it just had different artwork than the small binder I have from DP1, but to my surprise (and happiness) it's a full size, not a miniature! Now I have Dialga binders in both sizes, yay!
Vinyl Coin Purses
Source: Pokemon Center Tokyo, Yahoo! Japan, lineaalba of pkmncollectors
I picked a few of these up at the Pokemon Center on my second trip to Japan, one from pkmncollectors, and then several others from Yahoo! Japan. One I used to hold my coins on a trip to Japan - see it packed with yen there?
Metal Coin Purse
Source: Yahoo! Japan
A nifty metal coin purse with a zipper along the side.
Cloth Drawstring Bag
Source: Yahoo! Japan
This could probably be used as a DS case, but it's a bit big and the cloth at the top is a little too thin. It's got a nice unique design, though!
Clothing Buckets
Source: Yahoo! Japan
Although the clothes in here are way too small to fit an adult, I still like the metal bucket they came in (even enough to buy a second one of these expensive things!)
You can see some more pictures of the other sides here and here.
Meiji Candy Tin
Source: crunch385 of pkmncollectors
These tins originally contain Meiji fruit-flavored candies (フルーツドロップ, Fruit Drops), though this one has long been empty.
I actually had two of these tins well before I received this one, but one featured Dialga and Giratina (from the 11th movie) and the other featured Dialga, Palkia, and Giratina all together (from the 12th). I didn't realize there was a 10th movie version until Crunch found it for me and offered it in trade. Thanks very much!
Blue and Black Gachapon Pouches
Source: Yahoo! Japan
These pouches are two different gashapon sets. I originally thought they were supposed to be cell phone cases, but they're actually much bigger: they might hold a PDA or even (almost) a DS Lite.
The paint looks really neat and reflective on the black one.
Dice Bag
Source: ravestars85 of pkmncollectors
A cool bag featuring a very roaring Dialga!
Candy Tin (Yokohama Version)
Source: Pokemon Center (Yokohama, Japan)
This tin is part of a set of 6 Yokohama Pokemon Center exclusives. It's about 2" wide and filled with small candies!
Candy Pouch
Source: Pokemon Center (Hamamatsuchou, Japan)
A bag that you have to stuff with little candies. I tried to buy just the bag, but they insisted I fill it with candy to buy it! Regigigas is on the back.

Medal Holder
Source: Pokemon Center (Hamamatsuchou, Japan)
This little case holds a stamped penny (maybe more than one?) such as the Medialief Dialga on my flat items page. Why they made a case just for those is beyond me..maybe those pennies are more popular in Japan?

Pocket Chip Seal Sticker Set
Source: Daiei (Shiki, Japan)...I think
I was going to buy this sticker set anyway for the Dialgas in there, but it wasn't until later I realized that the case itself had a Dialga on it. Nifty!

10th Movie Promotion Lottery Purse / Handbag
Source: Yahoo! Japan
This bag is much bigger than the DS cases, and could be used as a full purse. Mine just hangs on the side of one of my Dialga shelves, though.

Dialga / Palkia Dice Box
Source: Hardrock-Pokemon
I was hoping that these two would separate and I could just keep the Dialga side, but the seller didn't know whether they would or not (he hadn't opened them, I guess) so I had to take a chance. I usually don't collect stuff that's only 50% Dialga, but since I already have this I'm letting it slide for now.