Transcript for Ryan Reynolds talks about switching it up in new movie 'Detective Pikachu'
I can assure all the parents out there, the only f-bomb I drop is fuzzy. Reporter: He is voicing detective pikachu. I know you can't understand me. But put down the stapler or I will electrocute you! I want to be the very best Reporter: First, a video game, pokemon is the highest-grossing franchise of all time. The multi-billion dollar poke-craze is beloved in comics, the game pokemon go and now a live-action film. And it all started here in I mean, if you buy a ticket to see detective pikachu in Japan, it's actually, it qualifies as a tax-deductible religious contribution. Reporter: You are so crazy. Just for everyone at home. If you are in Japan, write that off on your taxes. Reporter: Ryan and I met at sushi mafia in Tokyo. Oh. Wrong hand. Already. Come on. Get it together or get out! Hey! Reporter: See? I am like a bottomless pit for approval. Thank you so much. Reporter: Where we learned how to make sushi from a master. That's literally all I can see, there's a blowtorch around. I'm a child. I want to play with the blowtorch. Reporter: Would you say you and pikachu have anything in common? We have the same sized hands, which is weird. And we share a voice, that's for sure. Reporter: Where did you get the sense of humor that you have? I don't know. I'm just compensating. Reporter: For what? For horrifying things. Reporter: Well, some of the roles you've taken on are a bit horrifying. Those included the foul-mouthed super hero wade Wilson in "Deadpool." , . Language, please! Reporter: Known for his deadly swordplay. But pikachu is cute and cuddly. Ryan's facial expressions were translated to pikachu with motion-capture technology. I didn't need to go full Daniel day Lewis for this role. I didn't need to lose 180 pounds and dye my hair canary yellow. Reporter: I'm sure she would appreciate the canary yellow hair color. She would. Reporter: Blake as in Blake lively. Former star of "Gossip girl", and his wife of almost seven years. They have two daughters, and she was glowing at the premiere of detective pikachu, pregnant with their fourth child. My daughter was obsessed with it, I don't think she knows I'm the voice of pikachu. She just thinks I'm the voice of everything. It's going to be a hard-fought lesson at some point. Reporter: The film brings the animated universe of pokemon to life with humans and pokemon living together and teaming up to solve crimes. Oh, my clues! It's the first live-action pokemon film. So if you're a fan of pokemon or not, it's a new world. A new magical place we get to explore, and it's what it would be like if you had a pokemon in real life. Reporter: Justin Smith plays the partner. Along with Kathryn newton, they try to stay true to the original spirit. This is how I wanted to see these characters represented. If you're playing on the playground, imagining having battles with your friends. Reporter: Based on the fictional city. We shot it as a live action movie, and we got all the performances, and these guys did an amazing job. Justin and Kathryn acting to nothing sometimes. Thank you. That was probably the hardest part. You took that the wrong way. Hi, I acted with nothing. Every single day, every single second. Reporter: Back at sushi mafia, Ryan finally gets his hands on that blowtorch with that trademark mischievous gleam in his eye. I bet you didn't know when you took on the role of pikachu you didn't know were you going to be making nogiri. I'm having the time of my life. This is amazing. Reporter: For "Nightline," Adrian Bankert in Tokyo. Our thanks to Adrian. You can catch pokemon, detective pokemon now. Honoring mom this weekend,
This transcript has been automatically generated and may not be 100% accurate.