Crown Prince Naruhito and Crown Princess Masako alongside their pet dog Yuri at their residence in Tokyo’s Moto-Akasaka District in a video released to mark her 55th birthday (Provided by the Imperial Household Agency)

On her final birthday before she becomes the new empress next year, recovering Crown Princess Masako expressed her desire to dedicate herself to working for the happiness of the Japanese people.

“Giving thought to the days ahead, I sometimes feel uneasy about to what extent I will be able to be of service to people, but I will strive to do my best so that I can contribute to their happiness,” Masako said in a statement released by the Imperial Household Agency to mark her 55th birthday on Dec. 9.

Masako will become the new empress on May 1 when her husband, Crown Princess Naruhito, ascends the Chrysanthemum Throne following the abdication of Naruhito’s father, Emperor Akihito, on April 30.

Turning to her stress-induced "adjustment disorder," which she has been suffering from for the past 15 years, Masako said her condition is improving, albeit slowly.

“I am happy as I can now perform more official duties than before little by little,” she said.

A team of doctors treating her warned in a separate statement issued in time for her birthday that Masako “is still on the recovery track and there are ups and downs to her condition.”

The coming year is expected to keep her extremely busy with numerous ceremonies and events scheduled in connection with Akihito’s abdication and her husband's ascension.

The doctors said it is important that she not push herself too hard and continue with her therapy.

Masako said, “I will continue to work for my recovery and strive to do my best in performing as many official duties as possible.”

In a sign of gradual recovery, Masako made more public appearances this year by returning to events she used to participate in before she withdrew upon the diagnosis of her illness.

In May, she attended the Japan Red Cross Society annual meeting.

The following month, she issued a statement responding to questions from reporters on the 25th anniversary of her marriage to Naruhito on June 9.

On Nov. 9, when Akihito and Empress Michiko hosted their final garden party at the Akasaka Imperial Gardens in the capital, she walked the full route for the first time in many years despite the rain.

On the private front, she and Naruhito visited the exhibition of Seiji Fujishiro, a shadow picture artist, in Tokyo’s Ginza district incognito in early October. Masako, who looked relaxed and comfortable, gazed at an array of his works as the 94-year-old artist explained about them to the couple.

The crown princess has known Fujishiro for many years. She took Aiko, the couple’s 17-year-old daughter, to one of his exhibitions when she was still little.

“The crown princess is a person who tries to be her regular self,” the artist said, in describing Masako. “She appeared to be in hearty good health.”

Her doctors also stressed the importance of expanding her private activities, as well, for her continued recovery.

Psychiatrist Kaoru Sakamoto said adjustment disorder is an illness that people who are working hard to adjust to their environment are more prone to suffer from, despite the popular belief that it's people who cannot adjust to their surroundings who often fall victim.

“Anyone can be affected by adjustment disorder,” he said. “I am hoping that people will shake off their prejudice against the illness and support her fight” to overcome it.

Masako, born to a family of a top diplomat, spent many years overseas while growing up. After graduating from Harvard University, she joined the Foreign Ministry and worked there before marrying Naruhito in 1993.

In her statement, Masako also touched on social problems such as child abuse and poverty that she personally takes an interest in, saying people now live in a time that each should give serious consideration to realizing a society where all people can live without fear.

(This article was compiled from reports by Yasuhiko Shima and Ayako Nakada.)