Through the official Pokémon Times Twitter account, The Pokémon Company is hosting a special giveaway for fans in Japan. Those who follow @poke_times and retweet the corresponding tweets will be entered in for a chance to win one of 100 T-shirts. As shown in the picture above, the T-shirts consist of designs featuring Wobbuffet, Dratini or Abra. This giveaway is running until November 4, 2018.
Source: 【公式】ポケモン情報局 @poke_times