The thibg is, you need a cheating game system, or a game shark. If you do, you might be able to get in the door. When you are in, talk to the mirror of yourself. It will probably glich up, but just remember, this is a flaw of the Japanese makings.
Hope that helped!
Chat with our AI personalities
all you have to do is go into your secret base it says this is your secret base go in say yes then it says leave door open or close and decorate just select that.
No. however, if you leave your door open and someone finds it, they can come in to steal your flag.
You can find the key to unlock the door in Pokemon mansion
well they are secret bases but you need to teach one of ur Pokemon secret power(tm43), and u can get it in slateport city at the open market!(In Pokemon Sapphire).
you need an action replay