In the wrong hands, “The King and I,” with all those adorable children scampering about, could feel a little Disneyish. And then there’s the Yul Brynner problem. The show was originally written for Gertrude Lawrence, fanning the embers of her career, but it was Brynner, with his gleaming head and firm torso, who put his stamp on it when the show opened in 1951 and made a lifetime job of playing the King of Siam. He was still doing the role just months before his death in 1985, at the age of 65, and for all we know he’s doing it still.  How do you get audiences to let go of that hard-to-forget image and move on? Or for that matter, how do you get them to forget the 1996 revival, which starred Donna Murphy and Lou Diamond Phillips, who went on to make playing the king not a career, but a part-time job?  In his new revival of “The King and I,” which starts previews tonight at the Vivian Beaumont Theater and opens April 16, Bartlett Sher has solved the cutesiness problem the same way he made his acclaimed 2008 revival of “South Pacific” seem fresh and relevant — by going back to the Rodgers and Hammerstein vision and emphasizing how the historical subtext mirrors our world today. To step out of Brynner’s long shadow, he hired Ken Watanabe, a Japanese movie star who has never sung or danced before onstage and whose English is a work in progress.  This expensive-looking Lincoln Center Theater production, which also stars the silvery-voiced Kelli O’Hara, as American as they come and one of Broadway’s most appealing headliners, is not just the story of an English schoolteacher and a Siamese sovereign trying to overcome a cultural divide. Onstage those differences are really there.  “It’s a concern,” Mr. Sher said recently about Mr. Watanabe’s English. “We’re working with Ken all the time. But in the show, the king struggles with his speech. With Ken, you really feel that you have someone from an ancient kingdom meeting someone from the West for the first time. You feel the reality of that.”  For “South Pacific,” Mr. Sher’s casting hunch paid off, as the Broadway newcomer Paulo Szot won a Tony opposite Ms. O’Hara. Since then, though, his Broadway track record has been mixed; the new musicals “Women on the Verge of a Nervous Breakdown” and “The Bridges of Madison County,” which reunited the director with Ms. O’Hara, closed quickly.  Mr. Sher said he knew he wanted to cast Mr. Watanabe as soon as he saw him in the 2007 Clint Eastwood movie “Letters From Iwo Jima,” in which he plays, with great dignity and restraint, the general in command of the doomed Japanese force.  “I said to myself: ‘That guy’s a king,’ ” Mr. Sher recalled, and right away he flew out to Vancouver, where Mr. Watanabe was making “Godzilla.”  “Really?” Mr. Watanabe said to him. “In English? A musical? Oh no, no, no, I can never do this.”  In person, Mr. Watanabe is friendly, direct and disarming. But he is also a big, striking man who carries himself with confidence, and in early February, on the second day of rehearsal in a basement room at the Beaumont, he slipped a long purple robe over his hoodie and Hollister sweats, and instantly became a ruler.  He had already shaved his head, Brynner-fashion. He was worried that if he didn’t the audience might “hold back their feelings,” he said, and he hoped that this way he might lure them in. “It’s like come, come, and then you’ll get pulled into the maze,” he explained.  Mr. Sher, who is a tireless fusser and tweaker — and who believes that just getting an entrance right can explain a great deal about who a character is — had already discarded his work from the day before. Instead of opening the scene the way it’s usually done, with the king seated on his throne, he wanted Mr. Watanabe, attended by a kowtowing retinue, to walk the length of the Beaumont’s thrust stage.  Mr. Watanabe obliged with a stroll that was both regal and businesslike, and when he stopped to hear that the French had just colonized Cambodia (dialogue that Mr. Sher discovered in the original script and has restored to the show), he registered kingly alarm and annoyance at those predatory Europeans.  Shuffling across the rehearsal hall in stocking feet, arms at his side, his hands out like landing flaps, Mr. Sher nodded his approval. When he was out of Mr. Watanabe’s hearing, he said: “When we first started working, I thought, ‘Oh my God, this is maybe one of the best actors I’ve been around in my life.’ So many choices, so many things he can do. He’s got so much capacity for so many different kinds of work that it’s off the charts.”  In casual conversation, Mr. Watanabe can more than hold his own in English, but he likes to have his assistant and translator, Satch Watanabe (no relation) around just in case. Over lunch one day at a Japanese restaurant on the East Side, he explained that he grew up in Koide, Japan, a mountain town he compared to Denver, and that as a boy he studied the trumpet, hoping to become a musician. But when he was 13, his father, a calligraphy teacher, became ill, and there was no longer enough money for music lessons.  He decided to become an actor instead and was accepted into the very rigorous drama school run by the Japanese theater troupe En. He picked up a bit of English while studying Shakespeare there. “Just to get the feeling of those long lines,” he said.  But he didn’t begin to learn the language seriously until 2003, when he was cast in the Tom Cruise movie “The Last Samurai” (which, come to think of it, is a martial arts version of “The King and I,” with Mr. Cruise as a Western expert who finds himself falling for traditional Asian ways.)  “By then I was in my 40s,” Mr. Watanabe said, and laughed. “Too late.”  Before coming to New York, he began studying with a dialogue coach, Deborah Hecht, in lengthy Skype sessions. He still works with her and also practices most days with Satch. “I realized at the first read-through last summer how totally different is the language of stage English,” he said. “The breathing, the loudness.”  Explaining that the styles of Western and Japanese acting are very different, he went on to say: “I worry about my acting scale. Japanese acting is more like ink. You don’t need so much color. I express something this wide” — he held his palms a couple of inches apart — “but what’s the audience going to receive? More? Less? I trust Bart, but it’s still scary.”  “The Last Samurai” led to parts in several more American movies, including “Batman Begins,” “Inception,” and the forthcoming Gus Van Sant film “Sea of Trees.” Like Javier Bardem and Marion Cotillard, Mr. Watanabe has become something of a crossover star, though he is still far bigger in Japan, where he is also known for opening a restaurant in the tsunami-ravaged town of Kesennuma, to which he sends a fax, in Japanese characters, every day.  His appearance on Broadway is such news back home that a television film crew has been following him around New York, making a documentary.  Even by the end of the first week of rehearsal, Mr. Watanabe’s pronunciation had improved. He was working on the scene where the king first meets Anna, and Mr. Sher was encouraging him and Ms. O’Hara to be a little more playful.  “It’s like they’re fencing with each other,” he reminded them, and later he said: “You put a great Japanese movie star and a valued Broadway star together, and it’s an interesting mix. They’re finding each other. At first it was tricky, because she was trying to deal with the language and him, and all of that. But they’re getting there. So much of theater is rhythm, and probably the biggest challenge for Ken right now is to be in a new rhythm. It’s huge. You can see his head recalibrating. There are parts of this that are like Noël Coward — quick, quick, quick.”  During her lunch break one day, Ms. O’Hara said of working with Mr. Watanabe: “It’s like life imitating art, or vice versa. You couldn’t get more like the story. No matter how much he speaks English, you sense there’s a difference, especially when you’re talking about deep things, things about the heart, intensity, why we act. I keep wondering, How does he see me? Does he see me as inappropriate and girlish, running around without my shoes? Am I a spoiled American?  “But it’s all incredibly positive,” she added. “He’s such a collaborator and a fine and generous person. That’s something extra. We could have lived without it. But he’s rolling his sleeves up more than anyone and putting himself in a very risky position.”  By the end of February, when tech rehearsal had begun, Mr. Sher was still fretting, still revising. He was reminded that Mr. Watanabe’s contract runs out in July and that if the show is successful as everyone hopes, by May or June at the latest he needs to break in a replacement.  Mr. Sher started to say that sometimes when an actor remakes a role the way Mr. Watanabe is doing, it creates a template for someone else to step into, but then he stopped himself. “I don’t want to think about that now,” he said. “I just want to get to April 16.”  A version of this article appears in print on March 15, 2015, on page AR1 of the New York edition with the headline: Choosing a ‘Samurai’ to Portray the ‘King’. Order Reprints| Today's Paper|Subscribe
A movie star in Japan, Mr. Watanabe, who still keeps a translator nearby, makes his Broadway debut with a role about a cultural divide.