Iwao Hakamada worked at a soybean processing factory about two hours east of Tokyo when he was arrested and later sentenced to death for the grisly murder of his boss and the man's family.
Hakamada was 30 years old. The year was 1966. The US and Soviet Union were locked in a Cold War space race, Star Trek was in its first season and Japanese factories were busy pumping out a consumer gadget that would power its economic boom: colour televisions.
Nearly five decades later the Soviet Union is a relic of history, Star Trek is a global franchise, while Japan's world-beating economy is recovering from 20 years of tepid growth. And Hakamada, once a professional boxer, is a frail old man who spends his days in a solitary prison cell.
The 77-year-old is believed to be the world's longest-serving condemned inmate, a man supporters say has lost his grip on reality while awaiting death by hanging -- or old age -- even as questions over his guilt emerge.
"What I am worried about most is Iwao's health. If you put someone in jail for 47 years, it's too much to expect them to stay sane," Hakamada's now 80-year-old sister Hideko said outside the Tokyo Detention House.
Hakamada now refuses monthly visits from his sister and "talks nonsense", she said as rain fell outside the imposing prison in the Japanese capital, one of seven institutions across the country where condemned inmates are sent to the gallows. She last saw her brother almost three years ago.
"Before, when I asked him 'are you okay?', he said 'yep'. I only want to hear that single world," she said.
Apart from the United States, Japan is the only major industrialised democracy to carry out capital punishment, a practice that has led to repeated protests from European governments and human rights groups.
The death penalty in Japan is usually reserved for multiple murderers, including the masterminds of the 1995 sarin gas attacks on the Tokyo subway, which left 13 dead and thousands more injured. It carries out a handful of executions every year.
Japan's 134 death-row inmates face an austere existence, usually confined to their cell with little or no contact with other inmates. The strict regimen includes limited daily exercise and occasional entertainment such as being allowed to watch television.
Prisoners are typically notified about their impending deaths just hours before they are hanged. Their families are told only after the execution.
"Part of the problem in Japan is everything is still a little bit too secretive about the process," said Roseann Rife, Amnesty International's East Asia chief.
Sachie Monma, among a group of Hakamada's supporters gathered at the prison, added: "We must tell people how the death penalty works in Japan. If the public understood how cruel the system is, things would change."
A string of reprieves from death row in the United States have led some states to issue moratoria on capital punishment.
Despite a handful of death-row exonerations in Japan, capital punishment still draws broad support, although meaningful public debate on the issue is rare.
In 2010, then-justice minister Keiko Chiba for the first time allowed media to see the Tokyo prison's gallows in a bid to stoke a national discussion on the issue.
But ministers before and after Chiba have all shut down the idea of making executions more visible, fearing it would shock the public.
Current justice minister Sadakazu Tanigaki says capital punishment is necessary to satisfy public demands that violent crime be punished severely.
"I believe there are adequate grounds for the current system, considering the sentiment of the public and crime victims," he said after taking office in December.
However, Hakamada's case has raised troubling questions as new DNA evidence points to the once unthinkable: innocence.
Supporters are trying to get a hearing that would determine if he should get a retrial. Prosecutors say the testing method was faulty and stand by his conviction.
The tests found no match between Hakamada's DNA and samples taken from ill-fitting clothing he is alleged to have worn at the time of the crime, casting more doubt on his guilt, say supporters, including the Japan Federation of Bar Associations.
Even one of the judges who originally sentenced Hakamada to death in 1968 has said he was never convinced of the man's guilt but could not sway his judicial colleagues who outvoted him.
Back in 1966, Hakamada initially denied accusations that he robbed and killed his boss, the man's wife and two children before setting their house ablaze.
But he later confessed following what he claimed was a brutal police interrogation that included beatings.
He retracted his confession but to no avail. The Supreme Court confirmed his death sentence in 1980.
Japan has a conviction rate around 99 percent and claims of heavy-handed police interrogations persist under a long-held belief that a confession is the gold standard of guilt.
Last year, a Nepalese man was freed after spending 15 years behind bars in Japan for a wrongful murder conviction while, in 2009, an inmate serving the 17th year of a life sentence for a kidnapping-murder was released after DNA testing proved he was wrongfully convicted based on a false confession.
"I truly believe Iwao didn't do it. But once police suspect you for a crime, that's the end of the story. It was like that back then, it is like that now," his sister said.
Why authorities have not yet meted out the ultimate punishment in Hakamada's case remains unclear, although waiting years, sometimes decades, is not uncommon in Japan -- even though the law requires the sentence be carried out within six months of being confirmed.
Lingering questions about his guilt may also be a key reason that no official has signed off on his death warrant.
Meanwhile, time ticks on for Hakamada and his sister who fears the next hanging will end her brother's life.
"Every time I hear news of executions being carried out, I always worry, 'Is it Iwao?"