Princess Aiko, the only child of Crown Prince Naruhito and Crown Princess Masako, turned 15 on Thursday.
The princess, now a third-year student at Gakushuin Girls' Junior High School in Tokyo, has been learning more about carrying out official duties over the past year by accompanying her parents to activities.
The princess spent a busy summer vacation, accompanying her parents to the "Water Day" ceremony in the capital on Aug. 1 and to a "Mountain Day" event in Matsumoto, Nagano Prefecture, on Aug. 11.
In May, the princess visited for the first time the Peace Memorial Park near ground zero in Hiroshima on a school trip to learn more about the U.S. atomic bombing of the city on Aug. 6, 1945.
According to the Imperial Household Agency, Princess Aiko was absent from school from late September due to health reasons, but resumed class on Nov. 8.
The agency has attributed her absence to various causes including "fatigue from preparations for exams shortly after the summer vacation and for the school's athletic meet."
The princess initially attended afternoon classes but has recently begun attending school on a full-time basis, according to the agency.
