Note: This game is also titled .hack G.U. Vol. 1: Saitan.
At the desktop, hold R1 + R2 and quickly press Square, Triangle, Square, Triangle. Release R1 + R2, then hold L1 + L2 and quickly press Right, Up, Right, Up. Release L1 + L2, then quickly press L3 + R3. If you entered the code correctly, the Vol. 2 preview will be available in the media performer.
At the main menu, select the "Convert" option. Convert the saved game files from .hack//Infection, .hack//Mutation, or .hack//Outbreak to get an email from BlackRose that was sent to Kite after .hack//Quarantine. Convert a saved game file from .hack//Quarantine to also get that email in addition to an email from Hokuto sent to Rena. Note: In the Japanese version of the game, convert a saved game file from .hack//Fragment to unlock the email from Hokuto.
Convert a saved game file from one of the previous . hack games. When you fight Tri-Edge at the end, he will have the same name as your character from the previous .hack game.
To do this trick, you must not be able to afford the item you want, but you must, however, be able to afford at least one other item. You need to have enough GP so that if you used coupons on the desired item you would be able to afford it. First, start by selecting a buyable item as if you intended to purchase it. Then, add enough coupons so that if added towards the desired item, it would discount enough GP for you to afford it. Cancel the buy. Next, select the "unaffordable" item you want. It will appear as though you want to buy 0 of the item. Do not add coupons and confirm the buy. The item will no longer be in the shop inventory and will now be in yours. Note: If this trick is used on consumable items, they will not be usable by you; instead, the consumable item purchased with the above method will only appear when using any shop's "Sell" option. You will have 0 of the item but will be able to sell only one, no matter how many times you "purchased" the consumable before going to the shop.