Empress Michiko, the wife of Emperor Akihito and the first commoner to marry into the Chrysanthemum Throne, turned 74 on Monday.

Public comments are rare from the Japanese Imperial Family, whose members are cloistered and generally unavailable for media interviews, but most of them release statements through the Imperial Household Agency on their birthdays.

'The Crown Princess is a precious person for the Crown Prince as well as for our entire family,' Empress Michiko said in the statement. The prince's wife, Masako, has been suffering from depression for five years.

'I will continue to pray for the full recovery of the Crown Princess and will watch over her,' she said.

Princess Masako, 44, a former diplomat and Harvard graduate, has rarely been able to carry out her official duties, although she married into the family in 1993 with great fanfare as well as public expectations about how her brilliance would make her a role model for the modern Japanese woman.

Local tabloid magazines have been rife with stories about how she may have crumbled under pressure to produce a male heir to succeed Crown Prince Naruhito, Empress Michiko's eldest son.

After suffering a miscarriage in 1999, Princess Masako had a daughter, Aiko, in 2001.

Empress Michiko said she is also concerned about her husband, Emperor Akihito, who has been undergoing surgery and treatments for cancer for six years.

Empress Michiko - a frail but stately looking silver-haired woman pictured in a pale beige kimono for her official birthday photo - has also had her share of sickness.

In the early 1990s, she was unable to speak for months after suffering a nervous breakdown, reportedly over unflattering tabloid stories.

Last year, she suffered bleeding from the walls of her intestines, nose bleeds and mouth ulcers. The palace said the illness was stress-related.

On the positive side, in her birthday statement she said she gets great joy from her four healthy and happy grandchildren. Besides Princess Aiko, the empress's younger son Akishino has three children, two girls and a boy.

The empress said her granddaughter Aiko has much in common with her.

They seem to laugh at the same things, sounds of words, expressions, little things, she said.

'I glance at her, and she is looking at me with laughter in her eyes,' the empress said. 'Such moments make me feel so happy.' -- AP