The official Pokémon movie website has updated. Translations follow:

The "Get Pokémon with Namco!! Campaign" is Currently Underway at Namco Arcades

A "Get Pokémon with Namco!!" campaign is being held at Namco arcades until Monday August 1st!

If you put 500 yen in one of the specially marked crane game machines, you can enter the "Get Lottery"! You might win "original, limited Namco Pokémon merchandise" right then and there!
Go get Pokémon merchandise you can't get anywhere other than at Nacmo!!

The original, limited Namco Pokémon merchandise:


Original Namco Parka Towels (2 types)
Original Namco Beach Balls (2 types)
Namco Prizes: Check stores for details!

*The "Get Lottery" will only run while tickets last.
*The "Original Namco Parka Towels" and "Original Namco Beach Balls" are all limited in number and will only be given out while supplies last.
*The design and size of the actual products may differ from the ones in the pictures
*The pictures of the prizes are for illustration purposes only.
*The campaign may get changed or end without prior notice.
*Not all arcades will participate in the campaign.
*Prizes may only be redeemed at the arcade where the "Get Lottery" ticket was obtained.

Get Pokémon merchandise you can't get anywhere other than at Nacmo!!

*For further information on which arcades run the campaign etc, see the official Namco website.

Source: http://www.pokemon-movie.jp/news/?p=2233