Prince Hisahito turns 20 as Japan’s government reinforces male-only succession rules

TOKYO, September 6, 2026 - Prince Hisahito marked his 20th birthday on Sunday as Japan's government implemented controversial modifications to the Imperial House Law, solidifying the tradition of male-only succession. As the younger of 16 members in the dwindling imperial family, Hisahito is the second in line to the Chrysanthemum Throne, a line that has endured for over 1,500 years.

A fan of animals and insects, especially dragonflies, the prince is currently a sophomore in biology at the University of Tsukuba near Tokyo. Hisahito has been involved in a few official duties, attending events such as the palace banquet for Philippine President Ferdinand Marcos Jr. and joining a teenagers’ camp. Despite focusing mainly on his studies, the prince has started assuming certain responsibilities.

Hisahito has been frequently compared to his popular cousin, Princess Aiko, who is the emperor's daughter and has garnered admiration for her ability to connect with people. However, Princess Aiko is ineligible to succeed the throne as women cannot do so under the current rules. The recent revisions to the imperial succession law, enacted by Japan's Parliament in July, have sparked controversy.

The law permits the adoption of male offspring from distant former royal families and allows female royals to maintain their status after marrying a commoner. Yet, their future spouses and children will not be considered royalty. Critics have deemed the changes as outdated and sexist, with some protesting the alterations, backed by conservative Prime Minister Sanae Takaichi, as an attempt to exclude Princess Aiko from the line of succession while rationalizing gender discrimination and maintaining a patriarchal system.