Sakura Terakawa, 63, describes her four decades of married life in a small urban apartment as a gradual transition from wife to mother to servant. Communication with her husband started with love letters and wooing words under pink cherry blossoms. It devolved over time, she said, into mostly demands for his evening meals and nitpicking over the quality of her housework.

So when he came home one afternoon three years ago, beaming, and announced he was ready to retire, Terakawa despaired.

" 'This is it,' I remember thinking. 'I am going to have to divorce him now,' " Terakawa recalled. "It was bad enough that I had to wait on him when he came home from work. But having him around the house all the time was more than I could possibly bear."

Concerned about her financial future if she divorced, Terakawa stuck with their marriage -- only to become one of an extraordinary number of elderly Japanese women stricken with a disorder that experts here have recently begun diagnosing as retired husband syndrome, or RHS.

Feeling chained to the tradition of older women remaining utterly dedicated to their husbands' well-being, Terakawa said, she devoted herself to her spouse. Retirement cut him off from his longtime office social network, leaving him virtually friendless and her with the strain of filling his empty time. Within a few weeks, she said, he was hardly leaving the house, watching television and reading the newspaper -- and barking orders at her. He often forbade her to go out with her friends. When he did let her go, Terakawa said, she had to prepare all his meals before leaving.

After several months, she developed stomach ulcers, her speech began to slur and rashes broke out around her eyes. When doctors discovered polyps in her throat but could find no medical reason for her sudden burst of ailments, she was referred to a psychiatrist who diagnosed stress-related RHS.

Terakawa began receiving therapy from Nobuo Kurokawa, a physician who is one of Japan's leading RHS experts. Kurokawa coined the term retired husband syndrome in a presentation to the Japanese Society of Psychosomatic Medicine in 1991, leading to its use in books, journals and mainstream media here. Confirming Terakawa's account in an interview, Kurokawa said he offered her the same advice he has given numerous other older women in the same position.

"Come to therapy," he said. "Then spend as much time as possible away from your husband."

In Japan, retirement has become a risky business for many wives, who are finding the stress of their husband's presence at home unendurable. Though after-retirement stress is a common problem in most developed countries as husbands and wives try to balance relationships in their twilight years, analysts say Japan has become extraordinary for myriad reasons -- including the fact that one-fifth of Japanese are now over 65, the highest percentage in the world.

Even as gender roles have changed for younger people here, with women entering the workforce in record numbers, older Japanese have remained far more rigid. As with most Japanese men of his generation, Terakawa's husband demanded strict obedience from her, she said, even while he spent his life almost entirely apart from her and their three children. He left home for the office just after dawn and stayed out late socializing after work. He even took most of his vacations with colleagues and clients. Those long absences, she said, made his presence around the house after retirement even more jolting.

"I had developed my own life, my own way of doing things, in the years when he was never home," Terakawa said. She said she cannot even stand to look at her husband across the dinner table now and sits at an angle so she can stare out a window instead.

Part of the problem is that the nature of Japanese family life has changed dramatically over the past two decades. The tradition of retired parents living with their married adult children is rapidly disappearing, with new generations remaining single well into their forties and modern young couples choosing greater privacy. As older couples are forced to spend more time alone together, the divorce rate among those married more than 20 years -- a group that includes most of Japan's married senior citizens -- is now the fastest-growing in the country, more than doubling to 41,958 divorces in 2000 compared with 20,435 cases in 1985, according to government statistics.

Kurokawa estimates that as many as 60 percent of the wives of retired men may suffer from some degree of RHS.

With a record number of Japanese men set to retire -- almost 7 million from 2007 to 2009 -- experts warn that the disorder has the potential to explode. The Japanese boast the longest lifespan on Earth, yet older Japanese men still cling to the outmoded idea of wives as servile attendants -- leaving many elderly women to view their longevity as more of a curse than a blessing. One survey from the Tokyo-based advertising firm Hakuhodo showed that while 85 percent of soon-to-retire husbands are delighted by the idea of retirement, 40 percent of their wives described themselves as "depressed" by the prospect.

Fear of husbands coming home to roost has become a hot topic in Japan. Bookstores are loaded with self-help titles for elderly women attempting to cope with spouses who have turned into sodaigomi -- or bulky trash.

"This is a severe problem for us," said Sayoko Nishida, 63, an author of two books on the topic who has organized Zen retreats to help older couples deal with RHS. "One of the main issues is that we are not a culture where people directly express their feelings, and many older women have nowhere to turn to share their anxiety."

Tomohisa Kotake, a 66-year-old retired banker, knows the story well. "At first, I was a typical retired Japanese husband -- I didn't do anything for myself and asked my wife to serve me," he said. It immediately strained his marriage. Part of the problem, he said, was that his wife still had many female friends, but most of his friends had been work acquaintances. Pushed by his wife, he finally joined one of the more than 3,000 support groups that have recently sprouted up nationwide, aimed at "re-training" retired Japanese men to be more independent and communicative with their wives.

Kotake's group -- Men in the Kitchen -- taught him how to shop, cook and clean for himself. He now does the dishes and cooks for his wife at least once a week. "I will never forget the look of happiness in her eyes the first time I cleaned the house while she was taking a bath," he said.

Kotake's wife, Nobuko Kotake, 62, now speaks glowingly of her husband. She said she had given up many outings with female friends to spend more time with him.

"By Japanese standards, we are still relatively young even though we are retired," Tomohisa Kotake said. "We have a long life ahead of us. It is better that we spend that time enjoying each other. Doing more around the house is a small price for me to pay."

Retired banker Tomohisa Kotake, second from left, participates in a cooking class at a Men in the Kitchen support group meeting in western Tokyo.