Instructions
Enter any Poke Mart in the game. These buildings are usually located in towns and carry an assortment of items for sale.
Approach the counter and locate a notepad. Select it with the "A" button. The game will ask you to put in four random words.
Select the top left slot and write "LINK" in capital letters. Write "TOGETHER" in the top right slot, "WITH" in the bottom left slot and "ALL" in the bottom right slot.
Select "O" at the bottom of the screen. If the code is entered properly, the woman at the counter will give you the Mystery Gift.