Households in Japan: living units and family relationships

The 2020 census guidance groups people who share a residence and living expenses into a household. Friends who share a home may form one household if they share living expenses, or separate households if their finances are separate. Parents and adult children in the same building can also form separate units under the census rules.

A university student living in a separate apartment is counted as a separate household in the 2020 census guidance, even when parents send living expenses. A relative living and eating as part of another household can be included in it. Kinship, financial support and residence therefore describe different relationships.

The census distinguishes private households from institutional and other collective categories, with specific grouping rules for places such as dormitories, hospitals and social facilities. Private households can then be classified by composition, including one-person, couple-only and couple-with-children units. Neither one-person-per-household nor one-building-per-household captures the complete system.

The legal ie

The census household should also be distinguished from the historical legal ie. Under the former Civil Code, the household head exercised authority over family members and succession preserved that institution. Reform in 1947 dismantled it under principles of individual dignity and equality between the sexes; it did not instantly divide every extended household.

Postwar housing

Living conditions changed too. A Showakan exhibition linked postwar urban migration and new families with housing provision: the Japan Housing Corporation, established in 1955, supplied many small homes centred on two rooms plus a dining-kitchen. Legal reform, migration and housing describe different parts of the change.

Nuclear families before the war

Nuclear-family households already existed well before the postwar reforms. The population statistics collection records them as 55.3% of ordinary households in 1920: couples, couples with children, or a parent with children. That historical category is not directly interchangeable with today’s private-household totals, but it shows that smaller family living units were common while the legal ie still existed.

Changing household proportions

The Cabinet Office’s 2022 white paper compares private households in 1980 and 2020: one-person households rose from 19.8% to 38.0%, while couples with children fell from 42.1% to 25.0%. The denominator is households, not people, and children may be adults. The chart’s “three generations and others” category also includes other relatives and non-relatives; it is not simply three generations living together.

What the figures can establish

These figures describe changing distributions of living units. Ageing, marriage, migration and housing form part of the context, but two years of percentages cannot identify a single cause.