Japan prides itself on the world's longest life expectancy but is struggling with a disturbing footnote to that statistic - revelations that hundreds of people listed as its oldest citizens are either long dead or haven't been heard from for decades.
The mystery of the missing centenarians has captured the attention of this rapidly graying nation with reports of scamming relatives and overworked social workers and sad tales of old people, isolated and forgotten, simply slipping out of touch with society.
The story unfolded in late July when police discovered that Sogen Kato, who would have been 111 and was thought to be Tokyo's oldest man, had actually been dead for 32 years, his decayed and partially mummified body still in his home.
Police are investigating his family for possible abandonment and pension fraud.
That discovery led officials around the country to check up on the centenarians in their own districts, and what they found has been shocking.
The woman listed as Tokyo's oldest, Fusa Furuya, born in July 1897, is also missing. Her last registered residence was long ago converted into a vacant lot. In the western city of Kobe alone, officials are trying to track down more than 100 unaccounted-for centenarians, including a woman who, if still alive, would be 125.
That case and three others of 120-plus residents in Kobe are almost certainly examples of lax bookkeeping.
According to the Gerontology Research Group, which tracks individuals of extremely old age, the oldest person is 114-year-old Eugenie Blanchard, a French woman born on Feb. 16, 1896. She became the oldest after Japan's Kama Chinen died in May a week before her 115th birthday.
The confusion over Japan's centenarians has hit a sensitive nerve at a time when a growing number of people are living their last years alone.
Japan has 40,399 people aged 100 or older, according to last year's annual health ministry report marking Respect for the Aged Day, a national holiday on Sept. 21 - though that total now may be a few hundred lower.
"The families who are supposed to be closest to these elderly people don't know where they are and, in many cases, have not even taken the trouble to ask the police to search for them," the Asahi, a major newspaper, said in an editorial. "The situation shows the existence of lonely people who have no family to turn to and whose ties with those around them have been severed."
The Asahi also noted a sinister side to the problem. Unless death notices are filed with authorities, pension payments tend to keep coming, prompting some relatives managing older peoples' finances to keep deaths a secret.
The share of the population aged 65 and older hit a record high of 22.7 percent last year, while that aged 14 and younger has fallen to 13.3 percent - the lowest among 27 countries with more than 40 million people. Japanese women can expect to live 86 years, the longest in the world, and men nearly 80.
The graying of society and the low birth rate have brought an increasing number of social problems, strained government services and pension programs and raised worries about expected labor shortages in the near future.
Crime, alcoholism and suicide among the elderly are rising because of low incomes, unstable employment and poor living conditions.
Before World War II, about 90 percent of older parents lived with their children, a figure that has fallen below 50 percent today, said Katsuya Inoue, professor emeritus of psychology at Tsukuba University.
While that remains higher than in many Western countries, the rapid change has left many older people with few social ties and a porous support network.
"People used to take care of their aging parents. But with rapid changes in lifestyles, the very idea of taking care of one's parents seems to be waning," Inoue said.
The problem is exacerbated by a shortage of nursing homes.
The government has introduced a health insurance system to deal with ballooning medical costs for people over the age of 75, stepped up programs that encourage older citizens to stay active and is gradually extending the retirement age to 65 from 60.
But the recent revelations about the centenarians underscore how easy it can be to fall through the cracks.
Each centenarian receives a letter and a gift from a local government office, usually by mail. Little is done to confirm their circumstances, however.
Fewer than half of the country's 47 prefectures (states) regularly keep track of centenarians in person. Stung by the growing reports of unaccounted-for centenarians, Health and Welfare Minister Akira Nagatsuma has urged officials to find a better way to monitor the elderly.
"Many people have doubts whether the government properly keeps track of senior citizens' whereabouts," he said. "It is important for public offices to check up on them - where and how they are - and follow through all the way."
Nagatsuma suggested face-to-face meetings between local officials and all citizens over 110 years old to prove they are alive and well. Fewer than 100 people are believed to be in that category.