TOKYO – Princess Aiko, only daughter of the Crown Prince and Princess of Japan, has been absent from school for one month due to health problems, said the Imperial Household Agency, adding that her recovery will take some time.

Following medical advice, Aiko, who will turn 15 on Dec. 1, had stopped attending classes since Sept. 26 due to fatigue and weakness.

Aiko, who is a student of Gukushuin girls’ school in Tokyo, has been resting at home and although her condition is improving gradually, including her appetite, she continues to be weak, the Agency said, according to media reports.

Her mother, Princess Masako, canceled her visit to Iwate Prefecture last week to attend to her daughter, who in the past had faced problems in adjusting to her school.

For several months between 2010-2011, when she started elementary school, her mother had to accompany her to class daily after Aiko was bullied by some of her classmates.

Masako, often called the “sad Princess,” herself suffered from depression that led her to cut down on her public appearances and official commitments for more than a decade.

On Oct. 11, Masako attended a reception in honor of the Belgian royalty at the Imperial Palace in Tokyo, in what was her first appearance at such an event in two years.

Some blame her illness on the rigidity of the imperial protocol and the pressures she endured to give birth to a son to perpetuate the line of succession.