Japan’s Imperial family, the world’s oldest monarchy, has just marked a momentous occasion: Prince Hisahito, born on September 6, 2006, has become the first male royal in four decades to reach adulthood. Yet, as the nation celebrated his coming-of-age on September 6, 2025, a shadow of uncertainty loomed over the Chrysanthemum Throne. Many in Japan are now asking: could Hisahito be the last male heir, and what does that mean for the future of the monarchy?
Prince Hisahito’s journey to adulthood has been watched closely by the Japanese public and the world. A freshman at Tsukuba University near Tokyo, the prince is known for his keen interest in biology—especially dragonflies. According to the Associated Press, he’s co-authored an academic paper on a survey of insects found on his family’s Akasaka estate, and he’s also a fan of badminton. In his first official news conference in March, Hisahito expressed his hope to “focus my studies on dragonflies and other insects, including ways to protect bug populations in urban areas.”
Hisahito is the only son of Crown Prince Akishino, the current heir to the throne, and Crown Princess Kiko. He has two older sisters: Princess Kako and former Princess Mako, the latter of whom left the Imperial family upon marrying a nonroyal—a requirement under current law. The prince is also the nephew of Emperor Naruhito, who himself has only one child, Princess Aiko. This makes Hisahito second in line to the throne, behind his father. But here’s the catch: after Hisahito, there are no more male heirs in the immediate Imperial family, raising concerns about the monarchy’s future.
The elaborate coming-of-age rituals held for Hisahito on September 6, 2025, were steeped in tradition and symbolism. The festivities began at his family residence, where he donned a tuxedo to receive a crown sent by Emperor Naruhito. At the Imperial Palace, surrounded by royal family members and top government officials, Hisahito wore traditional attire—a beige robe that signified his pre-adulthood status. During the main ritual, his headcover was replaced with a black adult kanmuri, marking his transition to adulthood. The prince bowed deeply, thanking the Emperor for the crown and his parents for their support, pledging to “fulfil my responsibility as a royal member.”
Following the ceremony, Hisahito changed into formal adult attire and rode in a royal horse carriage to pray at three shrines within the palace compound. Later, he visited the prestigious Matsu-no-Ma, or pine room, to greet Emperor Naruhito and Empress Masako. In another postwar tradition, he received the Grand Cordon of the Supreme Order of the Chrysanthemum medal. The day’s events concluded with visits to his grandparents, former Emperor Akihito and former Empress Michiko, and a private family celebration hosted by his parents at a Tokyo hotel.
The coming days will see Hisahito undertaking more rituals, including visits to Ise Shrine—Japan’s most sacred Shinto shrine—the mausoleum of the mythical first emperor Jinmu in Nara, and the mausoleum of his great-grandfather, wartime Emperor Hirohito, in the Tokyo suburbs. He’s also scheduled to have lunch with Prime Minister Shigeru Ishiba and other dignitaries on Wednesday, September 10, 2025. The ceremonies have been both a celebration and a stark reminder of the challenges facing the royal family.
Why such anxiety over succession? The answer lies in the male-only succession policy, a rule enshrined in the 1947 Imperial House Law, itself rooted in the prewar Constitution of 1889. While Japan’s monarchy is over 1,500 years old and has seen eight female emperors—including the most recent, Gosakuramachi, who reigned from 1762 to 1770—none of those women produced heirs during their reigns. The current law prohibits female succession, despite public support for Princess Aiko, Emperor Naruhito’s only child, as a potential future monarch.
Historically, the male-only system was sustained by concubines, who, until about a century ago, helped produce imperial children. But as the Associated Press points out, that system is “structurally flawed” in modern times, especially as Japan faces a rapidly aging and shrinking population. The Imperial family now consists of just 16 adult members, and only Hisahito and his father are male heirs younger than the current emperor. Prince Hitachi, former Emperor Akihito’s younger brother, is next in line but is already 89 years old.
The succession debate has simmered for years. In 2005, the Japanese government proposed allowing female emperors, but the birth of Hisahito shifted the political climate. Nationalists and conservatives pushed back, and the proposal was shelved. A conservative panel of experts in January 2022 recommended maintaining male-line succession, but suggested that female members could keep their royal status after marriage and continue official duties. Another idea: adopting male descendants from now-defunct royal branches. However, the debate has stalled over whether to grant royal status to nonroyals who marry princesses and their children.
The impasse has left Hisahito shouldering an enormous burden. Former Imperial Household Agency chief Shingo Haketa told the Yomiuri newspaper earlier this year, “The fundamental question is not whether to allow male or female succession line but how to save the monarchy.” In May, the conservative Yomiuri issued its own urgent call for reform, urging parliament to “responsibly reach a conclusion on the crisis surrounding the state and the symbol of the unity of the people.”
Public sentiment, meanwhile, appears to favor modernizing the rules. Princess Aiko, who is hugely popular, remains ineligible to ascend the throne. The idea of allowing women to succeed, or at least to retain royal status after marriage, has gained traction. Yet, the political establishment remains divided, and no concrete reforms have been enacted.
The succession crisis is not just a family matter—it’s a national one. Japan’s monarchy is a symbol of unity, tradition, and continuity. As the population ages and the pool of potential heirs dwindles, the future of the Imperial line hangs in the balance. The coming-of-age of Prince Hisahito is both a milestone and a crossroads, forcing the nation to confront some uncomfortable questions about its past, present, and future.
For now, the young prince carries the hopes of a nation and the weight of centuries of tradition. As he embarks on his adult life—balancing the study of insects with the expectations of an entire country—the debate over succession is sure to intensify. The next chapter of Japan’s monarchy remains unwritten, but one thing is clear: the world will be watching closely as the story unfolds.