The JR East Pokémon Stamp Rally 2019 is a stamp-collecting event sponsored by JR East. Collect unique stamps in many of the JR East major train stations centered around the Tokyo metropolitan area. Stamp-collecting pamphlets are available in the station. Prizes and other rewards can be earned based on the number of stamps you collect. The stamp rally takes place from July 12th, 2019 until August 25th, 2019.

The stamps at each station and the Goal are outside the ticket gates. You will need a train ticket or Suica to reach each station. Stamp bootlets are limited to one per persons. Prizes are available while supplies last. Those that collect 6 stamps gets an Original Pass Case and those that collect all the stamps get a special Invitation-look folder for your stamp booklet.


Source: https://www.jreast.co.jp/pokemon-rally/