North America: Once you beat the first quest, you will continue immediately from the first stage of the second quest. The password to access this quest right away is: ABE4
Japan: When you beat the first quest, you are given a series of passwords, and then returned to the title screen. You must enter all three passwords in to access the second quest. They are: GYUW, then AGOG, and finally OOON. You must enter this code in and start a game on the first stage of the second quest, even if you intend to enter a password to access a later stage of the same quest.