Nintendo has been fighting the R4 piracy device and fighting it hard. There's a court injunction against the Chinese R4 makers for "violation under Japan's laws". Yahoo! Auctions is prohibiting the device's sale.
Earlier this month, retailers in Tokyo's geek mecca Akihabara were still carrying the device. However, stores are apparently trying to liquidate their inventory before it becomes illegal to sell R4 devices in Japan.
When it does, expect more scenes like this — guys in back allies, open car trunks, etc. And that cash register on a cardboard box? Classy.
「マジコン闇の市場」 フツーに売ってる秋葉原 [Akiba Blog]