Keiko Kawashima's job as a Persian-language court interpreter sometimes requires her to respond to calls in the middle of the night.

"It's not the kind of job that a homemaker can do on the side," said Kawashima, who receives requests to serve as an interpreter in trials involving Persian-speaking people from district courts in Tokyo, Chiba, Shizuoka and Kofu, Yamanashi Prefecture, as well as courts in Nagano Prefecture and Hokkaido.

Her assignments also require a great amount of insight into Islamic culture.