For a man who first made a name for himself at home and abroad as a staunchly noble samurai warrior, it's perhaps not surprising that actor Ken Watanabe appears comfortable in his latest theatrical role as a king.

It wasn't always this way, however. The 58-year-old star made his Broadway debut three years ago playing the titular character in Rodgers and Hammerstein's musical "The King and I" — a role he will reprise in London's West End this week. However, he readily admits to having had a few butterflies before first accepting the challenge.

"I was surprised (to be asked) at first," he says. "It was my first whole play in English, my first play in a foreign country, my first musical — that's three hurdles!"