Hey there,
Just recently inported the game and found this inside.
Not sure if anyone's translated it yet, but wanted to get this online to double check.

This was in with the booklet information, more or less assuming its an announcement/advertisement pamphlet.

Edited March 19, 201312 yr by hinokara

It's a code that unlocks some cards in the game or whatever. I doubt you'll ever be able to use it unless you find out a way to play the game when it's released in Japan.

It's a code but it's pretty useless if you don't get the jap version of the game.