Sixty-three-year-old Masatake Takei careened around the stage without his trousers, trying to beat off the angry mob of obasan (old ladies) who had just stripped him to his underpants. The audience obviously loved the spectacle, roaring with delight. But what was the president of a Tokyo architectural firm doing on stage in the first place, let alone in a production directed by world-famous Japanese dramatist Yukio Ninagawa? The same could be asked of the rest of the cast, comprised entirely of amateur actors in their 50s, 60s or 70s.

For Takei, it was all about finding a "life challenge."

"I did some amateur theater when I was a student, and ever since my business became stable when I was in my 50s, I have been wanting to do something exciting and make my life full of ups and downs again," Takei explained during a rehearsal last month. "Now, I do this until 5 p.m., then I go to my office in Mejiro until 10 p.m. or midnight."