India, July 17 -- Japan's parliament enacted a historic and contentious revision to the Imperial House Law on Friday, formalising a framework designed to stave off the collapse of the world's oldest hereditary monarchy while simultaneously cementing a rigid, male-only succession rule that has drawn widespread criticism.

The legislation, the first substantive update to the 1947 statute, permits female members of the imperial family to retain their royal status after marrying commoners, a significant shift from the previous law that forced princesses to leave the household upon marriage. Furthermore, the act introduces a mechanism for the adoption of male descendants from former imperial branches, a move the government claims is essential ...