There crap tons of art folders or other art folder like stuff all the time stores give this stuff away as like preorder bonus. I wouldnt even be supprised if stores like HMV Japan even gave away nice art calanders as free preorder bonus. Theres a crap ton of exclusive preorder crap and other stuff always giving away a akiraba districts in tokyo as well a lot of that stuff you wont find online ether as most of it you have to be physicaly present to even get it anyway. Japanese also don't seem to have a standard place to sell stuff like how we have ebay, Yes yahoo auctions may be the most popular auction website in Japan but still not enough gets posted on there compared to ebay because of rules banning foriegners from bidding and crap. ALso thanks for that link now i can probably find better information thanks to that link and probably better explain it to some of my Japanese friends.
Here are some of the strange promotional or ther stuff to try and convice japanese to buy stuff like here some assassins creed art work made 100% out of acrylic
