Tony award-winner Ron Richardson has done something very few American actors would even think of trying: He's relearned his lines in Japanese to bring a Broadway hit to Tokyo.

His performance as Jim, the slave friend of Huckleberry Finn, delights Japanese audiences and has made him and the musical "Big River" a bit success."When I walk out onto the stage and deliver my first line I hear a loud, swift intake of breath," Richardson said. "The audience is surprised to see a black man walk out onto the stage and speak in Japanese."

Richardson, who originated the role in the play which won the Tony for best musical in 1985, said audiences are also surprised by his booming voice, and, though generally more quiet and reserved than Americans, react with a lot of noise themselves when the show is over.

"They like me!" Richardson laughed. "We've been getting an incredible reaction. I think the Japanese forget that they are in Japan."

Before coming to Tokyo, Richardson, a 36-year-old native of Philadelphia, said he really didn't know what to expect.

"I came here with an open mind, wide open for experiences," he said in an interview. "I was prepared to make adjustments."

Richardson began studying Japanese last August, six hours a week at the Japan Society in New York. In November, he came to Japan on a promotion tour and got a chance to try out his new-found skills. Before coming back in February, he secluded himself on the Long Island shore for 2 1/2 months.

"It took me a very, very long time to learn my lines," he said. "I'm amazed I was able to do this. Up until the very end I really wasn't sure."

The only part of the show he didn't need to relearn was the songs. "I had to sing in English or else I wouldn't be able to make it. The songs in English give me time to regroup," he said.

Three other Americans are in the 29-member cast, but Richardson is the only one required to make long speeches in Japanese.

Success hasn't left much time to get out and see the country, but has given him a feel for Tokyo's workaholic pace. "With eight or nine shows a week, I only see Japan from my window."