On days he stayed home from daycare, retired chef Hideo Sakamoto kept to a familiar routine: a morning walk, a stroll around noon and an outing before dinner.?
On Sunday, April 16, 2023, he left home for that evening walk around 4 p.m.
He never came back.?
Though he had been diagnosed with early-stage dementia in 2012, the 73-year-old required no physical care. He remembered his own name and phone number and could dress and bathe himself independently.?
About 150 centimeters tall, Sakamoto wore black pants, a navy blue sweatshirt and a cap. He carried only an old-fashioned flip phone when he left the Nagasaki home he shared with his wife, Etsuko.
That afternoon, Sakamoto¡¯s daughter, Aiko Eto, was in another part of the city helping a friend run a gelato stand at a local market. Afterward, she went to dinner with her in-laws while her husband remained hospitalized following back surgery.
¡°Around 8 p.m., my mother called me, and everything became a blur after that,¡± Eto says. ¡°We were usually in constant contact, but for some reason she panicked and didn¡¯t call me right away.¡±
Earlier that evening, around 5 p.m., Eto¡¯s mother had called her husband after he failed to return home. He answered, but before she could ask where he was, he replied in the Nagasaki dialect that he was on his way home and abruptly hung up.
She called him two more times. Each time, he answered only to say, ¡°I¡¯m coming home,¡± before hanging up.
By around 6 p.m., she realized something was seriously wrong. The head of the neighborhood association, who also served as a local welfare commissioner, came to the house and advised her to contact the police. Sakamoto was reported missing shortly before 7 p.m., and officers soon arrived to begin taking statements.
Amid the confusion, Etsuko forgot to call her daughter. It wasn¡¯t until around 8 p.m., during a brief lull, that she finally remembered. Eto rushed to her mother¡¯s house.
What followed was an urgent search. Police officers and police dogs combed the area while Eto and her relatives retraced routes Sakamoto may have taken. Later came posters and social media appeals for information.
Three years later, he remains missing.
Dementia is a growing social challenge in the world¡¯s most rapidly aging nation, where an estimated 12.3% of people over 65 were living with dementia symptoms in 2022. That figure is projected to rise to 14.9% by 2040, according to the health ministry.?
Less visible is the increasing number of dementia patients who vanish each year ¡ª and the anguish endured by families left searching for answers, sometimes indefinitely. With dementia cases expected to keep rising as the elderly population grows, the issue has prompted calls for stronger coordination between police, municipalities and local communities.?
For Eto, 48, the ordeal eventually led her to form a support network for affected families.
¡°To be honest, I think part of my mother wants closure,¡± says Eto, who once ran a restaurant called Ishidatami with her father in Nagasaki. ¡°But watching her, I feel that true closure is impossible, and I can¡¯t help feeling sorry for her.
¡°She¡¯s 79 now, and when I think about whether she has another 10 or 20 years left, it¡¯s painful to imagine her spending the rest of her life burdened by this until my father is found ¡ª if he ever is.¡±
The danger of wandering?
In 2012, the year Eto¡¯s father was first diagnosed with dementia, 9,607 people with the condition had been reported missing nationwide. By 2024, that figure nearly doubled to 18,121, according to the National Police Agency. Of those cases, 491 people were later found dead, while 273 remained missing at the end of the year. A follow-up survey later found that 171 of those cases remained unresolved as of the end of 2025.
Many dementia-related disappearances involve wandering, a behavioral symptom associated with the condition. Once dismissed as aimless behavior, it is now understood to often reflect familiar routines, habits or destinations that still hold meaning for the individual.?
According to Kazunori Kikuchi, an adjunct researcher at the Tokyo Metropolitan Institute for Geriatrics and Gerontology, a person with dementia is not considered missing as long as caregivers or family members can still track their whereabouts, either directly or through tools such as GPS devices. A missing-person case begins when those responsible for the individual no longer know where they are.?
For people with dementia, wandering can stem from many causes rather than a single trigger, Kikuchi says. One theory, known as ¡°Need-driven Dementia-compromised Behavior,¡± suggests that wandering can occur when cognitive decline makes it difficult for people to recognize or respond appropriately to basic needs.?
¡°While healthy individuals can usually respond to needs such as hunger, discomfort or the need to use the bathroom, people with dementia may struggle to connect those needs with appropriate actions, leading to wandering behavior,¡± he says.
But wandering is not always driven by distress or confusion. Some people ¡ª like Sakamoto ¡ª may simply enjoy walking, follow longstanding routines such as daily exercise or dog walking, or set out intending to visit friends or familiar places. In such cases, what begins as a normal or meaningful activity can end with the individual becoming disoriented and going missing. People with mild dementia can also disappear, challenging the common assumption that such cases mainly involve those with more advanced symptoms.?
Research by Kikuchi¡¯s institute also found that the likelihood of death rises sharply the longer dementia patients remain missing.?
¡°The most common causes of death were drowning and hypothermia,¡± Kikuchi says.?
He believes people with advanced cognitive decline are more vulnerable to accidents because their ability to recognize and avoid danger is impaired, which may help explain the high number of drowning deaths, many of them occurring in rivers and waterways. Why drowning occurs so frequently, however, remains unclear.
By contrast, people with milder dementia may retain some ability to recognize immediate risks, making accidents less likely. But because they are also more capable of continuing to walk for long periods without being noticed or assisted, they may face a greater risk of dying from hypothermia after prolonged exposure outdoors.
Cases involving people who live alone were also more likely to result in death because it often takes longer for anyone to realize they are missing and begin searching for them. Many individuals are found alive within the first day after disappearing, but survival rates drop significantly after the third day.?
¡°That¡¯s why the most important factor is the initial response: beginning a search immediately after a person goes missing, including promptly notifying the police,¡± Kikuchi says. ¡°Every minute matters.¡±
Chasing sightings
The night her father was reported missing, Eto drove to her parents¡¯ home and immediately began searching the surrounding area with a flashlight. Police officers searched on foot and by patrol car while Eto retraced places her father was known to frequent, including his brother¡¯s house and the site of a former family home he sometimes tried to revisit. But as darkness fell and the streets emptied, the search became increasingly difficult. She returned briefly to her parents¡¯ house before resuming at dawn.
The following morning, police dogs joined the search. After losing Sakamoto¡¯s scent in a park about a 15-minute walk from his home, officers concentrated their efforts there while Eto and her relatives split into groups and coordinated through a LINE group chat. They searched neighborhoods across Nagasaki, a nearby mountain where her father had played as a child and even farther-flung areas, including the city of Sasebo, where he had driven alone to visit family graves.
For around two weeks, Eto spent nearly every day searching, sometimes walking 20 to 30 kilometers through Nagasaki¡¯s steep terrain. As official police operations scaled down after three days, she reluctantly turned to social media, posting appeals on Facebook, Instagram and X.
¡°It took a lot of courage to post about it,¡± Eto says. ¡°But once we did, information spread very quickly.¡±
Tips soon poured in from people claiming to have seen someone matching her father¡¯s description, prompting Eto to travel across the region chasing possible sightings. The family also distributed posters while Eto searched places tied to her father¡¯s old routines.
As days turned into weeks, the family¡¯s fears shifted from believing Sakamoto was merely lost to wondering whether he was still alive. Eto also found herself trying to support her elderly mother while managing the exhausting search effort. Over time, relatives and friends gradually returned to work and their normal lives, and new leads began to dry up.
Eto later contacted care facilities and other institutions in the hope that her father might have been admitted without identification, but privacy rules often prevented staff from sharing information without police involvement.
Some 3 1/2 months after her father disappeared, Eto agreed to her first television interview in the hope that publicity might bring new information.
¡°I thought maybe someone watching would recognize him,¡± she says.
The experience convinced Eto of the importance of speaking publicly about dementia-related disappearances and eventually led to discussions with Nagasaki Mayor Shiro Suzuki about gaps in support for affected families.
The city soon introduced a checklist outlining what to do when a person with dementia goes missing. Around the same time, Eto began building connections with others facing similar experiences.
¡°We all did whatever we could,¡± she says.?
In August 2024, 16 months after her father disappeared, Eto launched a nonprofit support association for families of people missing due to dementia. She called it Ishidatami.
Tracking hope
Responses to dementia-related disappearances vary widely across Japan. Some local governments have focused on prevention and community awareness, while others have introduced digital tracking systems.
In Omuta, Fukuoka Prefecture, officials have spent the past two decades building community-based programs centered on dementia awareness and early intervention. Since 2004, the city has organized annual ¡°wandering response drills¡± in which participants act out scenarios involving people with dementia who have become disoriented while walking through town. Residents, shop workers and even local elementary school students are encouraged to practice approaching and assisting them.
¡°The goal is not simply to search for someone after they disappear, but to create an environment in which they can safely reach their destination,¡± says Ryohei Kozaki of Omuta¡¯s welfare division.
The drills are designed to make people more comfortable approaching elderly residents who appear confused in public and to help communities recognize signs of dementia before a disappearance escalates into a police case. Omuta also works closely with nursing care providers and local welfare organizations through training programs focused on improving dementia care and strengthening community support networks.
¡°Because those connections exist on a daily basis, there are more cases where residents notice someone wandering and help them before they are officially reported missing,¡± Kozaki says.
Elsewhere, municipalities have turned to digital tools. In Shijonawate, Osaka Prefecture, officials operate three separate monitoring programs for people at risk of going missing.?
One involves QR-code stickers attached to clothing or personal belongings. If a person becomes disoriented, passersby can scan the code with a smartphone and send messages to family members through a digital message board system.
¡°We wanted a system that allows people to connect with families quickly while protecting privacy,¡± says Miyaka Oyabu of Shijonawate¡¯s elderly welfare division.
The city also participates in a program known as the SOS network in which families preregister photographs and identifying information about loved ones with dementia. If a person goes missing, local businesses, care facilities and other participating organizations receive alerts and watch for them during their normal activities.
A third program subsidizes GPS tracking devices that allow families to monitor a person¡¯s location through smartphones. According to the city, dozens of residents currently use the QR-code and SOS registration systems, and some families participate in multiple programs simultaneously.
Still, Eto says one of the biggest problems is that many families remain unaware of support systems that already exist, including the SOS network.
¡°We didn¡¯t know about the SOS network or GPS devices until after my father disappeared,¡± she says. ¡°There are systems in place, but they aren¡¯t reaching the people who need them.¡±
Technology may gradually make it easier to locate missing people as younger generations accustomed to smartphones and smartwatches grow older. At the same time, Eto warns that Japan¡¯s growing number of elderly people living alone could make disappearances even harder to detect.?
¡°I still don¡¯t know what the right answer is,¡± she says, ¡°but I think the first step is simply knowing what resources are available.¡±
Eto says her father was strict and stubborn, traits often associated with older men from Kyushu. ¡°But even so, he cared deeply about his family.¡±
¡°The sadness never goes away, and sometimes it turns into fear as I imagine what might have happened to him,¡± she says.?
¡°But I¡¯ve also met many people because my father went missing, and I feel those connections are something he brought into my life. So I try not to focus too much on the negative.¡±
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