Square Enix has updated the official Japanese website for Final Fantasy III DS, inculding the System Page. The page has been updated with a 'DS' page, which explains the unique game system control on the DS, which allows you to use the Nintendo DS Stylus to move characters and select battle commands. And how Movie Sequences are used with the Nintendo DS's two screens and how the the Game looks when your party is in the Shop. Older news as well, the page also informs us of the WiFi MogNet System. The MogNet page also shows how you can send mail through WiFi and to NPCs.

Source: Square Nexus