Heard about "Osu! Tatakae! Ouendan" this morning, and decided to see what availability and pricing is like on eBay right now. Then I see over a dozen auctions originating from Hong Kong, which I've flagged in the past as a pirate cart, due to GBA bootlegs being the norm.
I've never heard of this on the DS platform, though. Anybody know if these are actually legit, or are there DS bootlegs out there, now?