Starting on April 24th, 2017, participating stores will begin selling two different Pokémon GO branded Google Play cards. One card is for 5000 yen while the other one can be loaded with an amount between 1,500 and 50,000 yen.


Also announced is a special promotion that takes place from April 24th, 2017 until May 21st, 2017 where players can use the AR Mode in Pokémon GO and take a picture of a wild Pokémon next to a special Pokémon GO poster. Players can then Tweet their picture to the Google Play Pokémon GO Twitter account and the next time the player buys a Google Play card, they will get a 300 yen.


Sources: http://www.pokemongo.jp/topics/55/ and https://goo.gl/F5PbJM