Pokémon Centers are official retailers in Japan that sell, you guessed it, official Pokémon goods. Now there are five of these stores in Japan. Starting next month, there will be six.
On March 6, a Pokémon Center will open in Sapporo, joining Pokémon Centers in Tokyo, Osaka, Nagoya, Fukuoka and Yokohama. More info in the link below.
Pokémon Center in Sapporo [Pokemon.co.jp]