Forget Osaka's shady R4 cartridge retailers, the city has one shop that openly advertising the device. And thus, rubbing it in Nintendo's face in the process.
The R4 cartridge itself is not a piracy device; however, it can be used to play pirated Nintendo DS games.
A court injunction was filed in 2009 against Chinese R4 makers for "violation under Japan's laws". It's important to note that this legal injunction is for Japan only. Yahoo! Auctions Japan issued a notice that putting R4 devices up for sell on its site is now prohibited. Yet, the device was still widely available in Tokyo's Akihabara.
In late 2008, Nintendo (and 53 other companies) took legal action against the makers of the R4 cart, a device which allows, amongst other things, the pirating of games on a DS. Nintendo created an anonymous form for collect information about the sale of R4 cartridges in Japan. "It's getting increasingly difficult to track down R4 sellers as day by day they get more ingenious, flourishing online and complicating matters," said Nintendo in a written statement. Because of this, Nintendo is calling on the strength of the masses to eradicate the sale of these devices. This information will be used by Nintendo in its legal suit. It later thanked those for ratting out R4 retailers. According to Nintendo, such devices hurts the growth of the entire game industry and steps must be taken regarding the legality of R4 carts.
A new retailer in Osaka's Den-Den Town, which is the city's version of Akihabara, is hanging a huge banner that proudly states "R4 Majicon TTDS". ("Majicon" is how R4 devices are referred to in Japanese.) Last summer, a vending machine selling R4 cartridges appeared in Den-Den Town, but was later removed.