The eight-year-old granddaughter of the Japanese Emperor has become unable to go to school after suffering a series of anxiety attacks and stomach aches.
The Imperial Household Agency has revealed Princess Aiko's illness was brought on by the “rough behaviour” of her fellow classmates at the Gakushuin school she attends in Tokyo.
Little Aiko has been absent from the school since Monday.
The news comes as a further blow to the family of Crown Prince Naruhito.
The future emperor's wife Masako, a former Foreign Ministry high-flier, has been dealing with a form of depression for the last six years.