The official Pokémon movie website has updated. Translations follow:

Ride a JR East Train This Summer And Have Fun With Riddles! The "JR East Pokémon Riddle Rally: Save The Ingenuity Kingdom" is Starting Up!!

This summer, the "JR East Pokémon Riddle Rally: Save The Ingenuity Kingdom" will be held at JR East from Saturday July 23rd to Sunday August 21st!
It's produced by SCRAP of "Real Dasshutsu Game" fame!
The riddles take place over two stages! Walk around the participating stations and solve all the riddles!

Story:
The Ingenuity Kingdom is a country of giant cogwheels with 500 years of history to it. Peace is upheld in the Ingenuity Kingdom by Magearna! But one day, Magearna ends up abducted by someone! If she isn't rescued, the kingdom is going to get invaded! Use the information you gain from the Pokémon at the 7 stations and rescue Magearna!

Event time and dates:
Saturday July 23rd to Sunday August 21st
The rally is held from: The first train in the morning to the last train in the evening
Prizes can be redeemed at the goal station from: 10am to 4:30pm *please finish by 4:30pm on the last day of the event



How to participate:
1. Obtain a "Stage I Pamphlet" at one of the main stations in the Tokyo metropolitan area. (available from mid July)
2. Solve the riddles set up at 7 stations on the Yamanote line, find the secret code word, then head to the goal station.
3. Tell the secret code word at the goal station to receive a set of two "original Pokémon clear file folders" and a "Stage II Riddle Book".
4. Participants who then solve the Stage II riddles using the "Stage II Riddle Book" will receive a "certificate" at the goal station that proves they have passed Stage II.
(The event will end as soon as the supply of prizes runs out.)

The goal station:
You will find out which station is the goal station once you've solved all the Stage I riddles.
*The riddles, as well as the prize exchange location at the goal station, are located beyond the ticket gates. Event paticipants will need tickets to all stations, a Suica, etc.



For further information, see the JR East Pokémon Riddle Rally homepage

Source: http://www.pokemon-movie.jp/news/?p=2277