Mie Kurosaka, Rakuten Inc.'s first female executive, returned to work at Japan's biggest online mall operator only three weeks after giving birth in 2002.

Now, as one of Rakuten's four top female executives, the 47-year-old who oversees corporate social responsibility is pushing to have a nursery built inside its new Tokyo headquarters to provide better conditions for working mothers, she said in an interview.

Prime Minister Shinzo Abe will need more executives like Kurosaka to reach his goal of having women account for 30 percent of managers at the nation's companies by 2020. Employers should make it easier for mothers to continue working after childbirth, Kurosaka said, recalling her days of juggling early motherhood and work.