Princess Aiko of Japan, the granddaughter of Emperor Akihito and Empress Michiko, has been absent from school for over a month due to poor health.
An Imperial Household Agency official said that the 14-year-old princess has been suffering fatigue, caused by summer exam stress and the preparation for a school athletic event.
She has missed school since the end of September and earlier this month her mother Crown Princess Masako, who has battled anxiety, took her to hospital.
Princess Aiko, pictured in 2010, has been suffering from fatigue
According to Japan Times, Nobutake Odano, grand master of the Crown Prince's household, said that the princess "does not have to keep to her bed all day long. She took a walk in a garden for a little while yesterday".
No particular health problem was found, but a date for Aiko's return to school hasn't been set either.
"According to her doctor, although her condition has been improving little by little, it may take some more time for recovery," the official added.
Her mum Crown Princess Masako has suffered anxiety
This is not the first time Princess Aiko has been off school. In 2010 the then-eight-year-old princess missed classes amid claims she was being bullied by boys in her school. Aiko also complained of stomach pains and deep anxiety.
Her mother Masako, 52, was diagnosed with a stress-induced adjustment disorder, also known as situational depression, in 2004. Several reports claimed that the crown princess felt under pressure to produce a male heir.
Masako retreated from the glare of public life for years, but since 2015 she has been making a return to official duty, while she carries on with her treatment.
Last year on her 52nd birthday, she reflected on her progress, writing in a statement: "Taking care of my health, I have tried to fulfil my public and private duties as much as possible this year. With the help of people around me, I would like to continue making efforts to recover."