Yuka Suzuki, 47, has virtually no savings, earns about half the average national wage and cannot see where the money will come from to retire one day.

She is still doing better than most single moms in Japan, where half of all one-parent families live below the poverty line. The OECD ranks Japan — the world's third-largest economy — last among its 34 members for the financial well-being of single working parents, and the greatest hardship falls on mothers.

The laggard performance reflects a work culture skewed against women with children, a relative lack of support from ex-husbands and a dearth of child care facilities. While Prime Minister Shinzo Abe has made elevating the role of women as a pillar of his economic program, the initiative confronts entrenched attitudes dictating long hours for full-time workers.