Princess Aiko, the only child of Emperor Naruhito and Empress Masako, is pictured on Nov. 24, 2023, at the Imperial Palace in Tokyo. (Photo courtesy of Imperial Household Agency)(Kyodo)

TOKYO - Princess Aiko, the only child of Emperor Naruhito and Empress Masako, on Friday turned 22 amid her final year of university in which she is balancing her studies with a wide range of official duties as a member of the Japanese imperial family.