Later in the game game (I have no idea)a lab will apear in the store, then you will see a
machine, a cheats menu will pop up and put the p***words.

P.S. You will have to purchase the cards

a lab appears near the girls dorm (you will get an email from chanceler sheperd) all u
have to do is go down the stairs and to the right. there will be a machine for card
exchange (total rip; dont use it) and next to that is the p***word. just go to it and
press x as if to talk. the first option will be "p***word." then just enter p***word on
bottom of any yugioh card.
p.s. u can only rent 3 cards at a time and when u win a duel, dp will be deducted (i no it
****s :(

happy gaming!!