How to Get the Wonder Ticket in "Pokemon Diamond"
- 1). Travel to Jubilife City.
- 2). Go to the third floor of the Television Station and speak to the fat non-player character near the top of the screen.
- 3). Answer "Everyone's Happy" and "Wi-Fi Connection" to his questions. This will activate the Wonder Card/Mystery Gift system. Your friend can now trade you a Wonder Card by selecting the "Wonder Card" option and clicking "Send."
Source...