Japan’s popular Princess Aiko turned 23 on Sunday. The only child of Emperor Naruhito and Empress Masako, Aiko graduated from university earlier this year and has since been participating in official duties and palace rituals while working at the Red Cross Society, according to the Imperial Household Agency.

But Japanese law requires her to renounce her royal status and leave the family if she marries outside the imperial family. The vast majority of Japan’s public supports changing the law to allow her to remain a royal and become emperor, but conservatives in the governing party insist on keeping male-only succession. Japan’s rapidly dwindling imperial family has only 16 members, including four men.