Need help with the Nintendo DS digital keyboard

is it possible to have arabic characters on the Nintendo DS digital keyboard. I see players online with names written in japanese characters, while these characters don't exist on the original digital keyboard of the game I play (Yu-Gi-Oh 2010). These (japanese) characters must have been added later, somehow.
do you know how I can add arabic characters?

(A Nintendo DS Arabic Font exists on computer, for Microsoft Word, so the characters must exist for the DS.)