One morning in February, the government personnel department began an experiment in a nondescript building in a Tokyo residential area that could end up rewriting the rules of the nation¡¯s powerful bureaucracy.

For the first time, it invited 19 women from different ministries to an all-female training course designed to groom them for senior government positions. The four-day program inspired a 30-page blueprint, submitted to Deputy Chief Cabinet Secretary Katsunobu Kato, on how to fix a system that keeps government staff at work till late at night, sacrificing family life.

¡°We shared each other¡¯s sufferings, fears about our future, guilt about putting the burden on colleagues¡± when we left on time to care for children, said Noriko Kawamura, 38, an assistant manager at the health ministry. ¡°We began to realize that it was no good just grumbling about it, we had to do something. I never thought it would turn out to be such a big thing.¡±