Union officials and former teachers cite a major obstacle to the aspirations: Beyond the long hours and low pay, day care workers are often pressured or forced out of the profession for having babies of their own, subjecting them to discrimination in the very settings created to help mothers pursue careers.

The harassment is not limited to the day care industry. According to the Ministry for Health, Labor and Welfare, complaints against employers for demoting or telling women to resign because they got married or pregnant or gave birth have grown by more than 20 percent in the last decade — a statistic that only begins to capture the problem, experts say.

“In Japan, to go against your company on your own is very difficult,” said Kazuya Takemura, a lawyer who helped represent a Japan Airlines flight attendant who sued the airline when it forced her to take unpaid leave after she reported her pregnancy.

With its punishing hours and expectations to work well into the night, Japan’s work culture can be especially inhospitable to mothers.

“Once a woman gets pregnant and gives birth, it’s impossible for her to work in the same way as single women or male workers,” said Yumi Hasegawa, a lawyer who has worked on maternity discrimination cases. “That’s why the companies think ‘we don’t want such workers,’ and that leads to maternity harassment.”

But discrimination in child care centers has a particular domino effect — because it ends up blocking other mothers from being able to go back to work as well.