Japan changes its imperial family law for the first time since 1947

Japan’s parliament, the Diet, enacted a revision of the Imperial House Law on Friday 17 July 2026, the first substantive change to the statute since it was written in 1947, the Jiji Press news agency reported. The upper chamber, the House of Councillors, approved the bill a week after the lower house passed it on 10 July. The upper house vote was 184 to 57, according to the analyst Tobias Harris, writing in Asia Times.

The stated aim is to keep enough members in an imperial family that has been shrinking as its members age and as princesses leave on marriage. The revision does this in two ways.

First, it lifts a ban on adoption. The family may now adopt men descended in the male line from the 11 imperial branches that were removed from it in 1947. An adoptee must be at least 15 and have no spouse or children. He cannot inherit the throne himself, but his sons can: Chief Cabinet Secretary Minoru Kihara told the Diet that “male children of adoptees are eligible to succeed to the throne.”

Second, the article that required women of the family to leave it when they married has been deleted. Their husbands and children will remain ordinary citizens. Succession itself is unchanged and stays restricted to men in the male line.

The ruling Liberal Democratic Party and several other parties supported the bill. The Constitutional Democratic Party of Japan, the Japanese Communist Party and Reiwa Shinsengumi voted against, and some opposition parties objected that the succession rights of adoptees’ descendants had not been discussed in the cross-party talks the government cited as its basis. Jiji reported that each chamber deliberated for only about three hours. Prime Minister Sanae Takaichi called the passage “deeply moving”, Harris wrote. A supplementary provision requires a review every 30 years.