It's a red storage case - based on the photo showing the '99 BK toys on the packaging, circa 1999 or 2000. I believe, though I have no proof, that this was sold by Walmart - as was a lot of classic Pokemerch - but seems hard to find on the internets.
So I'm tossing this out there to see if anyone's seen one around! In as good shape as possible, but I'll look at anything. This case was the center of my collection as a kid, it's how I carried all my toys and cards around with me everywhere I went! I'd love to have it back! I know it seems a bit silly compared to things like pokedolls and pokecen plush, but I'm hoping that a bit of crowdsourcing might help out a bit ^w^ It's one of the closest things to a grail that I currently have just because it's been so hard for me to find!
Thanks in advance for any information that anyone might have!