Pokémon Diamond and Pearl/Amity Square

At the north east and north west of Hearthome city there is a gate that leads to Amity Square, there are certain pokemon that can only be entered, these are: Pikachu, Clefairy, Psyduck, Pachirisu, Happiny, Buneary and Drifloon, but there is a secret, if you walk around for about 200 steps if you speak to your pokemon it may be holding a berry or a fashion item like red feather, kts really good because it makes your pokemon love you more, and there are a few items lying around,.