Already happening............
obtian the mystory event
It's an event-only item.
check serebii.net for info on upcoming events for Pokemon Diamond,Pearl,Platinum.
you need to have the event (dont know what event it is) hope it helped
There is no information available on Nintendo holding another Secret Key event in the future.
To get the secret key, you can go to nintedo wifi and mystery gift there
sorry that was a one time thing.
it was through a Nintendo distribution event and it has already passed...
The Secret Key was only available during the Rotom Pokemon event that took place last month. Now, the only way to get it is to hack for it.
Pokemon event
You can only get the secret key in Pokemon Platinum
There is a cheat for obtaining the Secret Key. You can use Action Replay Codes for WI-Fi Event Items.