When you 'debug' your tamagotchi, you take off the backing and rub a little circle with a pencil. You are then able to choose your character, and fast forward in time.
I haven't had my tamagotachi debugged for a while, but if I remember properly, when it the egg first hatches, you and it says 'boy' or 'girl', then you press the 'a' button and you can choose a character. To do this you will need to reset your tamagotchi, and try again.
