The scenario was a landowner’s dream. A new trunk road was coming to Greater Tokyo and a small patch of scrubby grass, good for nothing much else, lay directly in its path. A bit of gumption, an able lawyer and Japan’s transport ministry would have to pay up.

In fact, says Uichiro Masumoto of the ministry’s land and construction bureau, a stubborn landowner would have been great news. The reality was much worse: there was no landowner. The plot in question was last registered in 1904 to a woman born sometime in the reign of the Meiji emperor.

Bureaucrats burrowed into archives. They ultimately came out with 148 heirs — which was only the start of their difficulties, because eight of them had emigrated. Almost 200 letters and interviews later, the government gave up. A court order let the road go ahead. The process took three years.