Kodokushi: What Japan's Official Numbers Actually Say

What the figure counts — and what it doesn't

There is no single legal definition of 孤独死 (kodokushi) in Japan. Different agencies count different things, which is why English-language coverage of this subject varies so widely. The figures on this page come from one source with one consistent definition: the National Police Agency's Criminal Investigation Bureau, which since 2024 has published an annual count of 警察取扱死体のうち、自宅において死亡した一人暮らしの者 — among bodies handled by police, those of people who lived alone and died at home.

That definition is broader than the popular image of kodokushi. It includes deaths discovered the same day. It includes deaths where family were called within hours. It is a count of people who died alone at home, not a count of people nobody missed. In 2025 the count was 76,941, of whom 58,919 — 76.6% — were aged 65 or over, and 17,860 were under 65.

One widely-repeated number needs correcting. The figure 37,227 circulates in English coverage as though it were an annual total. It is not: it is the National Police Agency's provisional half-year release covering January to June 2024 only. The annual figures are 76,020 for 2024 and 76,941 for 2025.

How long before someone was found

The most useful thing in the police data is not the headline count — it is the distribution of 経過日数, the days between death and discovery. This is the part of the problem a check-in can actually speak to.

Most people were found quickly. In 2025, 28,398 of the 76,941 — 36.9% — were discovered on the day of death or the day after. But the tail is long. Summing the published age-by-days table, 22,222 people (28.9%) were not found for eight days or more; 7,148 (9.3%) were not found for over a month; and 208 were not found for more than a year.

Among the 58,919 aged 65 and over, 22,502 were found within a day, while 15,911 — 27.0% — were not found for eight days or more.

These totals for the 8-day and 31-day bands are our own sums of the National Police Agency's published age × days-elapsed table; the agency publishes the bands separately rather than as cumulative figures.

Why this is a timing problem, not only a medical one

Japan's numbers describe, at national scale, the thing that makes living alone different: not that something goes wrong more often, but that when it does, there may be no one in the room. The international clinical literature on this is consistent. In a prospective study of people in their 90s, 82% of falls happened when the person was alone, 80% of those who fell could not get up unaided, and 30% lay on the floor for an hour or more (Fleming & Brayne, BMJ 2008). Among older people who fell at home and lay there for more than an hour, about half died within six months (Wild, Nayak & Isaacs, BMJ 1981). And time-to-discovery is itself the sharpest lever: among people found helpless or dead at home, mortality was 67% for those down more than 72 hours, against 12% for those found within an hour (Gurley et al., NEJM 1996).

The police data cannot tell us how many of the 76,941 would have lived had they been found sooner — it records deaths, not preventable ones, and many were expected or instantaneous. What it does show is the scale of the discovery gap: on the government's own count, more than one in four people who died alone at home in Japan were not found for over a week.

What a daily check-in can and cannot do

A check-in is a narrow tool, and it is worth being precise about its limits. It cannot prevent a heart attack, a stroke or a fall. It does not summon an ambulance. It is not a substitute for Japan's 見守り (mimamori) services, for family, or for a neighbourhood association.

What it does is compress the discovery window. If you confirm you're okay once a day and one day you don't, the people you chose are told — within hours, not weeks. Against a distribution where 22,222 people went more than eight days without being found, that is a meaningful and honest claim, and it is the only one we make.

I'm Alive is a daily check-in app. You confirm you're okay once a day; if you don't, the people you chose are told, with your location. The daily check-in is free (Try It, $0) and works on iPhone and Android anywhere in the world. Automatic alerts to your contacts start on Protect Me ($29.99/year), with location on the move on Protect Me On The Move ($39.99/year); there is a one-time Stay Connected lifetime upgrade at $4.99. Check-first phone fall detection is live on iPhone only (app v2.3.1) on Protect Me and above, and stays off until you switch it on. It alerts your own trusted contacts — it never calls emergency services, and it is best-effort, not a medical device. The app interface is currently in English only.