At the main menu of the game, click "Password" and enter a combination of symbols to unlock outfits/character in your game. Codes usually come from Guide Books, Slip that came with the game, or on the back of cards that were given out at Mcdonalds in Japan.

Effect	Password
Unlocks 'Mcdonalds' Blue Dress	Flower, Ribbon, Boat, Ribbon, Heart, Star
Unlocks Bikini	Flower, Clover, Moon, Clover, Moon, Sun
Unlocks Fairy Shirt	Boat, Flower, Ribbon, Star, Clover, Clover,
Unlocks Rose Shirt	Ribbon, Star, Clover, Boat, Flower, Boat
Unlocks Santa Dress	Heart, Sun, Ribbon, Star, Boat, Flower
Unlocks Yuri/Cure Moonlight	Sun, Star, Clover, Flower, Heart, Boat