The first study of its kind, commissioned by the ministry of health, labour and welfare, also showed that most municipalities did not have an established protocol for dealing with the bodies, including how long they should be kept before cremation.

Of the roughly 1,160 municipalities surveyed by the Japan Research Institute, only 11.3% said they had a procedure, while 43.5% said they did not. Others answered that although they did not have their own rules, they referred to practices elsewhere.

Municipalities have also struggled with concerns that relatives may try to claim bodies after they have been cremated.

The 41,969 unclaimed bodies, both identified and unidentified, made up 2.7% of all deaths in the 2023 calendar year, and the need for a system for handling them is growing, with the number only expected to rise in the coming years.

The National Institute of Population and Social Security Research forecasts that 23.3 million out of 52.6 million households, or 44.3%, will be single-person households by 2050.

Among municipalities with a system for handling them, Yokosuka, near Tokyo, launched a programme in 2015 in which the city assists in contracts between funeral homes and low-income elderly people with no dependants.

Under the programme, the city will check on their well-being and contact necessary people and institutions in the event of their death.

“The number of cases in which there are no families to take care of funerals will continue to increase,” said Kazuyuki Kitami, a welfare officer in the city. “It is important for municipalities to create systems that will value a resident’s dignity and intentions.”