If you caught this week's debut of Monarch: Legacy of Monsters, you've probably already noticed that it seems like the show has a breakout star: Mari Yamamoto.

Yamamoto, who's also appeared in Apple TV+'s Pachinko, plays a scientist named Keiko who is just as likely to run after monsters than run away from them, and she simply sparkles on screen. Popverse recently had a chance to chat with some of the people behind Monarch: Legacy of Monsters, and we were curious to hear what they had to say about casting Yamamoto in the show.

"We auditioned a lot, a lot of people, and we narrowed in on Mari towards the end of the process," Monarch's casting director Ronna Kress shared. "It was a point when we were now doing auditions live, but Wyatt really insisted on reading with Mari. He felt like it was an important piece, so we all COVID tested. They were in my office, and that really, I think cinched it for us, once we saw them as a couple. But she was amazing right from the start, and I totally believed her as the character. And you'll see as you watch all of the episodes, you'll know she really is heroic in many ways in our story."

Showrunner Chris Black added, "I can't say enough about her talent, and working with her, and just how delightful she is as a collaborator and how much she brings to creating that character. She was great, and it really was seeing that chemistry when she and Wyatt Russell came in, and not that we didn't already know she was the one, but when Wyatt came in and they got in the room together and did soem scenes together, that just cinched it."

Monarch: Legacy of Monsters is currently streaming on Apple TV, with new episodes debuting each Friday.

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