Prince Hisahito of Japan, nephew of Emperor Naruhito, has formally reached adulthood at the age of 19—becoming the first male royal in four decades to do so. As the second in line to the Chrysanthemum Throne, his milestone has reignited debate over Japan’s 19th-century male-only succession law. At a ceremony Saturday, Hisahito received the traditional kanmuri crown from the Emperor’s envoy. In his remarks, he said, “As an adult member of the Imperial Family, I will fulfill my duties with a sense of responsibility.” The prince later donned ceremonial attire at the Imperial Palace and is scheduled to pay respects at the Ise Grand Shrine, Emperor Jimmu’s mausoleum, and the tomb of his great-grandfather, Emperor Showa. He will also meet Prime Minister Shigeru Ishiba and other dignitaries. With no younger male heirs in line, calls are growing to amend succession laws that exclude women despite Japan’s shrinking imperial family.