A new news article has been posted!
From
Saturday April 25th, 2015 until Wednesday May 5th, 2015, the Trophy Pokémon Tretta Gift Campaign (トロフィーポケモントレッタ) will take place at
Pokémon Centers and Pokémon Stores in Japan. Patrons need to play
Pokémon Tretta at least once or purchase at least one Tretta related product in order to get 1 of 6 Trophy Tretta's at random.
Zekrom, Reshiram, Darkrai, Volcarona, Victini and Charizard are the 6 Trophy Tretta's being distributed.
Source:
http://www.pokemon.co.jp/info/2015/04/150410_p02.html