Japan's revised law to maintain imperial family size takes effect

Japan's revised Imperial House Law entered into effect on Saturday, aimed at addressing the declining size of the imperial family while preserving the male-only succession system. Enacted in July as the first major revision of the 1947 law, the legislation permits the imperial family to adopt males aged 15 or older from 11 former imperial branch families, descendants of emperors through the male line.

Notably, female members can retain their imperial status after marrying commoners, reversing the previous requirement that they relinquish their status upon marriage. However, adopted members and their male descendants are ineligible to become emperor themselves; eligibility is limited to male descendants of eligible imperial ancestors.

The revised law does not consider female emperants or succession through the maternal line, maintaining the tradition of male primacy. The revised imperial system will be evaluated every 30 years if needed. The revision bill, drafted through cross-party consultations, introduced provisions on male descendants of adoptees, sparking criticism from opposition parties.

The coalition agreement between the Liberal Democratic Party and Japan's Innovation Party, led by Prime Minister Sanae Takaichi, mandated the revision. Despite only three male heirs to the throne, Emperor Naruhito, Crown Prince Fumihito, and Prince Hitachi, succession remains a contentious issue, with Japan's hereditary monarchy tracing back over 2,600 years, despite occasional female emperors.