Passwords (JP)
In the main menu, go to the passwords setting and enter the password for a variety of thing to happen:
2115 4585 - Celebi appears in the entrance area
1670 3396 - Darkrai appears in the House Zone
8037 3821 - Pikachu's Balloons in Pelipper's Sky Flap Race
4169 5651 - Pikachu's Snowboard in Empoleon's Snow Slider
7887 2252 - Pikachu's Surfboard in Gyarados' Marine Slider