About a million people die every year in Japan, and 10 percent of them leave wills (yuigonsho). That's a smaller portion than in the English-speaking West — the BBC says about a third of British adults have wills and USA Today reports 59 percent of American baby boomers have written them — but it's still larger than other Asian countries (about 1 percent in South Korea) and the number is growing every year.

Legal experts advocate wills as the only effective means of properly disposing of one's assets after death, but in Japan they've traditionally been seen as disruptive. Japanese law outlines methods of inheritance and even stipulates shares for specific family relationships. But family ties have been strained in recent decades owing to shifting social demographics and economic trends. A recent article in the Asahi Shimbun reports that more and more people are dying without any clear beneficiaries. In 2012, ¥37.5 billion left behind by people who died was taken by the government because the deceased had no family willing to claim the body and the person's property. According to the Supreme Court, this amount is three times what it was a decade ago.

When a person dies without spouses or children, or when those heirs have forfeited their right to the deceased's assets, the proper court appoints an administrator to dispose of the estate. If the deceased had debts, the administrator repays them out of the available assets. If the deceased had a caregiver, the administrator may offer the person part of those assets. But for the most part the unclaimed money and proceeds from property goes to the central government.