Ken Watanabe is set to join Ryan Reynolds in Detective Pikachu Ken Watanabe (Inception) will join Ryan Reynolds (Deadpool) in the cast of the upcoming Universal Pictures Pokémon movie, titled Detective Pikachu, according to THR. The film will be released in U.S. theaters on Friday, May 10, 2019. Fans familiar with the franchise, those who have kids or those who obsessively played the recent hit mobile gaming app Pokémon Go, know that Pikachu is a type of Pokémon.