Nintendo has opened it’s very own online sale store for Japan.
Here you can buy Wii, 3DS and Nintendo DS products direct from the store. The shop focuses on accessories and items that you can’t usually find in a retail shop, such as replacement instruction manuals. These are available at ¥105 each. The shop also stocks a lot of older products for the Game Boy Advance and GameCube. Unfortunately this online store is for those who live within Japan and does not ship internationally.