In this summer’s first sci-fi thriller, Ken Watanabe stars in “Inception” with Leonardo DiCaprio as the lead, directed by Christopher Nolan, known for thrillers such as “Memento” and “The Dark Knight.” Watanabe has taken on the role of Saito, a powerful business mogul in the energy industry who needs Cobb (DiCaprio) to plant an idea in a rival magnate’s mind (played by Cillian Murphy) by entering his dreams and manipulating his subconscious. In order to ensure the job is done properly, Saito accompanies Cobb and his team (Joseph Gordon-Levitt, Ellen Page, Tom Hardy and Dileep Rao), and we are led through unpredictable labyrinth worlds of the dreaming mind.

Watanabe, born in Koide, Japan, is easily a household name in Japan, and is widely known for his samurai roles in works such as “Dokuganryu Masamune” (“One-eyed Dragon Masamune”), a 50-episode television drama series. Watanabe captured the world’s attention with his work in “The Last Samurai” as Lord Katsumoto Moritsu, followed by his role in “Memoirs of a Geisha” as the Chairman, and his lead role in “Letters from Iwo Jima” as Gen. Tadamichi Kuribayashi.

In addition to receiving an Academy Award nomination for Best Supporting Actor for his work in “The Last Samurai,” Watanabe won the Japanese Academy Award for Best Actor twice, once in 2007 for “Memories of Tomorrow” and again in 2010 for “Shizumanu Taiyō.”

While he has filmed movies for both Hollywood and Japan in a variety of roles, acting in both Japanese and English, Watanabe’s approach to every film he acts in is consistent.

“When working on a movie, I try to think of how this movie will affect a single audience member,” the actor told the Nichi Bei Weekly in a phone interview conducted in Japanese. “No matter what country [the movie] is shown in, I think that the human emotions, the feelings that are shared while watching a film, are universal. As a result, I don’t believe there is anything I necessarily do differently [working in both Hollywood and Japan].”

The role of Saito shows subtle complexities in character that Watanabe nuances beautifully through his acting. Even in increasingly dangerous situations, Saito carries himself with a calm, unscrupulous confidence, keeping an eye on Cobb while slowly realizing that in order to survive, he must trust him. Watanabe observes, “At first, it’s only a business relationship, but as the story continues, Saito and Cobb develop an understanding and a respect. They need each other.”

Watanabe takes his craft seriously; he is the penultimate professional when thinking about his character. “As this character, [I ask myself] how do I interpret and keep up with Chris Nolan’s imagination and world?”

Given the subject matter and story of the film, it’s clear that this is no simple task. “It’s like riding a Nolan-roller coaster. You just have to get on the ride to really experience the world [that he has created].”

Watanabe first worked with Nolan in 2005, cast as Ra’s al Ghul in “Batman Begins.” Nolan enjoyed working with him so much that when writing “Inception,” the role of Saito was written specifically with Watanabe in mind. Accepting the role was an easy decision for Watanabe. “When Chris called and asked me to join him, it was easy to say yes, because it was a wonderful opportunity to work with a director I loved working with before. And after I read [the script], I was even more pleased. So my heart and my head told me I definitely had to do this movie.”

“Inception” features spectacular shots of different scenes throughout the world, taking audiences through the narrow, winding, market alleys of Tangiers, Morocco, along the café-lined streets of Paris, and up to the snowy alpines of Calgary, Canada. Filmed in six countries with the accompaniment of elaborate sets, the making of “Inception” was an enormous undertaking, requiring different production crews for each location and requiring actors to work in extreme climates and demanding circumstances, which included shooting through blizzards as well as working in a set that rotated a full 360 degrees.

“From the first shoot in Tokyo to the final shoots in Calgary, I went to every location. [Filming this movie] was like going on a long journey,” Watanabe said.

While work has kept Watanabe travelling throughout the world, he generally divides the rest of his time between Los Angeles and Japan.

Watanabe’s role in “Inception” is a significant film role for an Asian actor this year. Unlike previous Hollywood films where Watanabe was cast in more traditional roles as various Japanese men, the character of Saito is completely different from what American audiences have seen from him so far.

“Within Hollywood films, it was the first time I acted in a contemporary role, and I’m hoping to have that opportunity to act in that kind of role again,” he said.

The character of Saito truly allows the audience to see yet another facet of Watanabe’s dexterous skill as an actor, and has people buzzing about what he will be working on next.

“I am always anticipating that interesting roles will come my way,” he reflected. “Keeping that in mind, with each and every role I accept, I always go with the mindset that it will be my very best performance yet.”