From Bulbanews, your community Pokémon newspaper.
Distribution to be from August 10 to September 6
The official Japanese Pokémon website has announced that the Pokémon Center will distribute four Pokémon from the Best Wishes series. Ash's Pikachu, Iris's Axew, Cilan's Pansage, and Professor Oak's Rotom will be available for players of Japanese versions of Black, White, Black 2, and White 2 between August 10 to September 6, 2013. The distribution period will be split into four weeks where players can randomly get one of the four Pokémon each week. In addition, the player can receive a special seal when they present the Pokémon to a Pokémon Center staff member. The Pokémon received can also be traded with other players.