Seems my suspicions were correct as this is from the Tyranitar deck:
I wasn’t aware that these were available in unlimited at all. I can only assume the Steelix deck has an equivalent unlimited print. This means that for me I need to find 3 more Pokémon Collector cards and 2 more Pichu cards which will likely be very, very difficult to pin down.
To go with @nullifidian 's Cyndaquil and Totodile, I’ve just picked up this Chikorita from YJA:
The listing had 4 of these available, actually, so I’ve bought all 4 in the hope that firstly the seller hasn’t already sent the pictured card out, and secondly more than one of them might be unlimited.
The seller has over 60 other individual L1 cards up for sale, but this was the only unlimited variant they had. I find it interesting that we now have definitive proof of the 3 starters existing but no other cards.*
* Aside from the 2 Pichus and 2 Pokémon Collector cards PSA has marked as unlimited from this set.
I’m wondering if there was some other product released around the time of this set which would have contained these unlimited cards.
I don’t think we should be quick to assume that these were only available from the Toys R Us gift packs. Another product released 8 months after HGSS was released in Japan was the “LEGEND Perfect Set” which features 1 of each LEGEND booster pack. It’s unfortunately not possible to see if these are 1st Edition packs, however: www.pokemon-card.com/products/legend/legend_ps.html
If anyone has 13000 JPY to burn, there’s one for sale on YJA right now which has a close-up image of the packs:
Interestingly there’s a blog post here from someone in Japan who has opened one of these: pkmnsz.blog59.fc2.com/blog-entry-982.html
Unfortunately the image they’ve shared of the best card they pulled has the area where the 1st Edition stamp would be cropped out:
There’s also the Random Basic Pack, which has a stock image which features no indication that the cards contained are 1st Edition: www.pokemon-card.com/products/legend/l1_rbp_cardlist.html
The only copies I can find for sale right now though are clearly marked as 1st Edition:
I think that where they made extra Steelix and Tyranitar Constructed Decks in unlimited it could be safe to assume that they also released these in unlimited?
@pichufan for the random basic pack I’ve only ever seen the stock images with no 1st ed stamp never and actual photo so if they do exist in unlimited they would be incredibly rare I would imagine. Is there a deck released in the era that has the L1 starters in it but uses numbered set cards and not a separate numbering system?
My thoughts exactly, however I’ve also never seen an unlimited Tyranitar deck which my unlimited 016/019 Pokémon Collector I shared above must be from (simply because I don’t believe there were any other ways to get that card). The stock images for those also always omit the 1st Edition stamp.
To my knowledge, no. I believe the Japanese Pokémon website lists all of the available products released at this time: www.pokemon-card.com/products/legend.
There were 6 decks released around this time: the Steelix and Tyranitar Constructed Decks, 3 Battle Starter Decks and the Leafeon vs Metagross Expert Deck which all featured their own numbering system and do not include any of the cards we’ve identified so far except for Pokémon Collector (which in the case of the Steelix and Tyranitar decks counts as L2 and not L1).
Another purchase I’ve made recently shows another unlimited Pokémon Collector card, but this one has the set info cropped out so I’ll have to report back on what it’s from when I get it:
When I first heard about those unlimited L1 cards I went searching a bit right away. I also came across two of those boxes, but the packs were a bit more visible and were all 1st edition. So not sure if this product is available with unlimited edition packs, but the two I’ve seen both had all four packs as 1st edition. EDIT: Here is one of those, where you can see the (partial) 1st edition stamp on all four packs:
As for the Random Basic Pack, the unlimited edition pictures I see are always the same stock image. Never an actual photo. And the sellers I messaged which responded stated they were 1st edition. It’s rather similar with this stock image of the unlimited edition E1 Pikachu I see pretty often on Yahoo Japan, for which the description of the auction always states 1st edition…
I’ve also seen a WCP unlimited edition Seviper once on a US website, but the website mentioned the 1st/unlimited edition would be random for all Japanese cards after I contacted them… Sellers and webshops like that I avoid as the pest. It’s like stating you can either get a 1st edition Shadowless Base Set Charizard or an unlimited edition Base Set Charizard. The price difference is immense… The same applies to these unlimited edition Japanese cards, although in reverse where unlimited edition is rarer than 1st edition, unlike English sets. For the unlimited edition cards I’m still missing (E1 Pikachu, L1 Pikachu, L1 Reverse Holo Pikachu, WCP Seviper, and WCP Battle Frontier) I would pay 100+ USD easily. But for their 1st edition counterparts I sell some of them myself of which I have 10+ copies for 50 cents each… 
Greetz,
Quuador
Do you have any other pictures of this particular listing? I’m wondering if there is a 1st Edition stamp on the packaging elsewhere.
I absolutely hate this, those sellers really aren’t helping us.
I’ve learnt to just ignore any stock-looking image of E1 cards at this point.
I managed to find a sealed Steelix Constructed Deck in unlimited, so I’ve happily picked this one up:
I can’t find any instance of an unlimited Random Basic Pack, but that’s my best guess right now. When I looked around a few weeks ago I couldn’t find any unlimited Steelix or Tyranitar decks either (not even on Mercari’s sold list), but since then the one I just bought has popped up.
I’m not convinced unlimited packs were from the DPt Toys R Us box speculated above simply because those were originally released in November 2008, almost a year before L1 was released. It’s peculiar that the one @shizzlemetimbers shared has that sticker on, as none of the sealed boxes I’ve come across so far have had that (or have they had any indication that they include L1 booster packs).
Here is the auction on eBay with more images. But I don’t see any 1st edition stamps on the packaging itself.
Same. Especially of one seller in particular which has unlimited edition E1 pictures for almost all his auctions, like he’s doing it on purpose knowing they are rarer…
Nice find, but isn’t that L2 instead of L1? I’m able to find L2/L3 cards, and actually have around 15 myself in my collection. I also know @supersaiyanampharos collects unlimited edition L2 and L3 cards as his main focus, although I haven’t seen him online in a while, so not sure if he’s still collecting. I’ve sold him some of my duplicated copies once.
Greetz,
Quuador
Yeah it is L2 but some of the artwork it uses comes from L1 (like Pokémon Collector which I’m interested in); I was aware of unlimited L2 and L3 booster packs, but I wasn’t aware of unlimited Steelix/Tyranitar decks until Tristan’s post - I guess I just wasn’t looking hard enough not knowing they might exist.
@quuador that user hasnt actually been online since March so I dont think they are collecting anymore.
Ha, so when searching for “Japanese HeartGold unlimited cards” on Google Images I got excited when I saw this:
Unfortunately it links back to our very own forum. Here precisely: www.elitefourum.com/t/japanese-unlimited-legend-series/14490/1
I’ve trawled through that thread and can’t find this image anywhere. It might just be the awful quality, and perhaps I’m only seeing what I want to see, but this image does appear to show Pichu, Pikachu, Crobat, Hypno, Unown, Igglybuff, Jigglypuff, Wigglytuff and Meowth from L1 in unlimited. Curiously, all of these are from
SoulSilver Collection, not HeartGold Collection (however Tristan’s Totodile already proves that unlimited can also come from HeartGold Collection).
It would be very interesting to know who uploaded that image and why they appear to have deleted their post.
I don’t think anyone has posted that image in that thread, since I’ve also participated in that thread and on that very page, and it isn’t even that long ago (February of this year). I do see the same image when I use your search term on google image, and it indeed links towards that page. Weird…
I even looked in the source code of the website for that page if I could find this image, but unfortunately not. It’s probably a related search result for one of the other auctions linked, which is why the quality is so bad because it’s a tiny thumbnail picture. Not really sure why google doesn’t go to one of those links directly in that case though, instead of the Efour forum.
Btw, the quality is too low to say whether it’s 1st or unlimited edition. That Wigglytuff is 1st edition for sure, but for the others I’m unable to tell with that quality. Unfortunately the 1st edition symbol of the L1/L2/L3 sets are the smallest of all Japanese sets, with the same size as the copyright dates… 
I have the feeling the cards in that picture are 1st editions however. Although I’m not entirely sure. My eyesight is good, but even I can’t tell whether those few black pixels are the 1st edition symbol or shadows in the card itself…
Greetz,
Quuador
I don’t see it listed in the OP, so I’m wondering if Dragon Selection (DS) might also be a false 1st Ed. set?
I can’t for the life of me find a single unlimited Japanese card in this set.
Confirmed that Wild Blaze has unlimited cards. Can remove from OP.
Hi! What about BW2 (red collection)
Does it exist in unlimited?
Also BW4, cant find any unlimited cards from my research.
Any help would be much appreciated
You might be correct these don’t exist in unlimited edition. I personally don’t own any; I have 43 cards from Red Collection and 35 cards from Dark Rush in my general Pokémon collection, but all are 1st edition. I also haven’t seen any, but since neither of these sets contain any Pikachu nor Seviper cards, I obviously haven’t looked very hard for them. But it’s likely these only exist in 1st edition indeed.
I’ll add them as “1st edition only” in my article, but if someone find even a single card in unlimited edition from either of these BW2 or BW4 sets, lmk.
Greetz,
Quuador
Sorry I’m bumping this thread again but I’ve been doing a lot of research on unlimited L1 cards and I can’t find anything. I feel like the biggest hurdle is the fact that Japanese have no word for “unlimited”. I couldn’t even find a single mention of which sets have 1 st edition and which not (in Japanese). Where did you find this picture? Do you know who has those cards?
Quick question, is L3 confirmed unlimited? Cause if so… then there’s a new rarest Celebi for me to track down
Yes, L2 and L3 are available as unlimited edition. And yes, the Reverse Holo unlimited edition Celebi Prime card is most likely a pain to find, so good luck. 
Greetz,
Quuador
I’ve also been searching for unlimited edition L1 cards for the longest time without much luck. Only the Chikorita, Cyndaquil, and Totodile non-holo cards have emerged in unlimited edition thus far, so I’m assuming they had some kind of special release, and none of the other L1 cards were released in unlimited edition. The Cyndaquil and Totodile in the picture you quoted are in @nullifidian 's collection I think, and the Chikorita is in @pichufan 's collection.
Greetz,
Quuador