The official Pokémon movie website has updated. Translations follow:

LINE Stamps Celebrating the Movie Premiere are Here!

Original LINE stamp celebrating the premiere of "Mewtwo Strikes Back Evolution"
will be available in the internal LINE stamp shop starting Thursday July 4th!

These famous scenes have been turned into stamps?!



The Pokémon are cuter and cooler than ever now that they're depicted in 3DCG.



We also get a full lineup of Satoshi, Kasumi, Takeshi and the Rocket Gang, all making their first ever appearances as Pokémon stamps!



Check out the internal LINE stamp shop right away and aim to be the ultimate Stamp Master!

The stamp shop can be found here: https://line.me/S/sticker/14702

Stamp lineup:



Product information:
Product name: Original "Mewtwo Strikes Back Evolution" LINE stamps
Usage cost: 240 yen (tax included) or 100 coins/set
How to download:
The stamps can be downloaded from the internal LINE stamp shop.
Store url: https://line.me/S/sticker/14702
Notes:
*The stamp shop is only available for LINE for iOS, Android and Windows Phone
*Please update to LINE version 2.7 or higher when using this function.

Source: https://www.pokemon-movie.jp/news/?p=3664