"The insurance system in Japan is very lax when it comes to paying out for suicide," he says.
"So when all else fails - some people feel - you can just kill yourself and the insurance will pay out.
"There is sometimes an intolerable pressure on the elderly that the most loving thing they can do is take their lives and thereby provide for their family."
But it is not only elderly men in financial trouble who are taking their own lives.
The fastest growing suicide demographic is young men. It is now the single biggest killer of men in Japan aged 20-44.
And the evidence suggests these young people are killing themselves because they have lost hope and are incapable of seeking help.
The numbers first began to rise after the Asian financial crisis in 1998. They climbed again after the 2008 worldwide financial crisis.
Experts think those rises are directly linked to the increase in "precarious employment", the practice of employing young people on short-term contracts.
Japan was once known as the land of lifetime employment.
But while many older people still enjoy job security and generous benefits, nearly 40% of young people in Japan are unable to find stable jobs.
Financial anxiety and insecurity are compounded by Japan's culture of not complaining.
"There are not many ways to express anger or frustration in Japan," says Mr Nishida.
"This is a rule-oriented society. Young people are moulded to fit in to a very small box. They have no way to express their true feelings.
"If they feel under pressure from their boss and get depressed, some feel the only way out is to die."
Technology may be making things worse, increasing young people's isolation. Japan is famous for a condition called hikikomori, a type of acute social withdrawal.
The Japanese Ministry of Health, Labour and Welfare defines hikikomori as people who refuse to leave their house and isolate themselves from society in their homes for a period exceeding six months
According to government figures released in 2010, there are 700,000 individuals living as hikikomori with an average age of 31
An overlapping group of people with the hikikomori, otaku are "geeks" or "nerds"
The young person affected may completely shut himself - it is most often a male - off from the outside world, withdrawing in to a room and not coming out for months or even years.
While hikikomori is mostly a Japanese phenomenon, cases have been found in the United States, Oman, Spain, Italy, South Korea and France
"So when all else fails - some people feel - you can just kill yourself and the insurance will pay out.
"There is sometimes an intolerable pressure on the elderly that the most loving thing they can do is take their lives and thereby provide for their family."
But it is not only elderly men in financial trouble who are taking their own lives.
The fastest growing suicide demographic is young men. It is now the single biggest killer of men in Japan aged 20-44.
And the evidence suggests these young people are killing themselves because they have lost hope and are incapable of seeking help.
The numbers first began to rise after the Asian financial crisis in 1998. They climbed again after the 2008 worldwide financial crisis.
Experts think those rises are directly linked to the increase in "precarious employment", the practice of employing young people on short-term contracts.
Japan was once known as the land of lifetime employment.
But while many older people still enjoy job security and generous benefits, nearly 40% of young people in Japan are unable to find stable jobs.
Financial anxiety and insecurity are compounded by Japan's culture of not complaining.
"There are not many ways to express anger or frustration in Japan," says Mr Nishida.
"This is a rule-oriented society. Young people are moulded to fit in to a very small box. They have no way to express their true feelings.
"If they feel under pressure from their boss and get depressed, some feel the only way out is to die."
Technology may be making things worse, increasing young people's isolation. Japan is famous for a condition called hikikomori, a type of acute social withdrawal.
The Japanese Ministry of Health, Labour and Welfare defines hikikomori as people who refuse to leave their house and isolate themselves from society in their homes for a period exceeding six months
According to government figures released in 2010, there are 700,000 individuals living as hikikomori with an average age of 31
An overlapping group of people with the hikikomori, otaku are "geeks" or "nerds"
The young person affected may completely shut himself - it is most often a male - off from the outside world, withdrawing in to a room and not coming out for months or even years.
While hikikomori is mostly a Japanese phenomenon, cases have been found in the United States, Oman, Spain, Italy, South Korea and France