Prince Hisahito of Akishino

Prince Hisahito (悠仁親王, Hisahito Shinnō, born 6 September 2006) is the youngest child and only son of Prince Fumihito and Princess Kiko. He is the nephew of Emperor Naruhito and second in line to become emperor of Japan after his father.

Hisahito, the Prince's personal name (chosen by his father), in this case means "serene and virtuous", according to the Imperial Household Agency. An alternative translation is "virtuous, calm, everlasting". The emblem on the Akishino family crest that is used to mark the Prince's belongings represents the Japanese umbrella-pine tree (kōyamaki).

Prince Hisahito is the only son and youngest child of Fumihito, Prince Akishino, and Kiko, Princess Akishino. He has two older sisters, Princess Mako of Akishino and Princess Kako of Akishino. He was first seen in public on 15 September 2006, outside Aiiku Hospital.

Hisahito was the first male child born to the Imperial House of Japan since his father in 1965. In January 2007, the Prime Minister of Japan, Shinzō Abe, announced that he would drop an earlier proposal to alter the Imperial Household Law so as to allow females to inherit the throne.The proposal had been made on the basis of the fact that the two sons of Emperor Akihito had, at the time, no sons of their own. Given Hisahito's birth, it now seems increasingly unlikely that the laws will be changed to allow Hisahito's cousin, Princess Aiko, the daughter and only child of the Emperor Naruhito, to become a reigning Empress and thus end the Japanese succession controversy. The supporters of changes criticized the current law as it placed a burden on the few aging males old enough to perform royal duties as females left the family.

In the spring of 2010, Prince Hisahito began kindergarten at a school affiliated with Ochanomizu University in Tokyo; on 14 December 2012, the Imperial Household Agency announced he would enter Ochanomizu University Elementary School in April 2013 so he could be with many of his friends from kindergarten. The prince thus became the first member of the Imperial House of Japan to receive his education at a school other than Gakushūin Primary School, which is also in Tokyo. By his second year, he was reported to be doing well at school, helping to look after first-year pupils and playing with his friends. In April 2019, Hisahito was enrolled in Ochanomizu University Junior High School. Police reports indicate that there was an assassination attempt on him there.

Hisahito is styled as His Imperial Highness Prince Hisahito of Akishino.