The official Japanese Pokémon Website has revealed the Famitsu Challenge (ファミ通チャレンジ) online tournament for the Japanese versions of Pokémon X and Y. Registration is done via the Pokémon Global Link, and requires a Pokémon Daisuki Club membership account. All participants will receive a special "Famitsu Challenger" medal on their Global Link medal list.


Region: Japan
Registration Period: April 10th, 2014 until April 18th, 2014 at 8:59
Tournament Period: May 18th, 2014 until May 21st, 2014 at 8:59
Max number of participants: 50 000
Player divisions: Junior (players born in 2003 or later), Senior (players born between 2002 and 1999) and Master (players born in 1998 or earlier)
Battle Type: Double Battle
Pokémon Restrictions: Pokémon caught or hatched from eggs in Kalos
Banned Pokémon: All Pokémon not found in the Central Kalos, Coastal Kalos or Mountain Kalos Pokédexes, as well as Mewtwo, Xerneas, Yveltal, or Zygarde.
Entry Gift: Famitsu Challenger Medal

UPDATE: A Holo Caster message was sent out informing of this tournament. It can be found on our Holo Caster page alongside all other such messages.

Source: http://www.pokemon.co.jp/info/2014/03/140320_e01.html