When does old age begin?
The stereotype of people in the last phase of life is they are enfeebled and ill. However, Japan's senior citizens refuse to conform to this image.
Tanaka Yuki, who is 99, is still on the door at a stalactite grotto and running a convenience store on the outskirts of Tokyo.
Former Japanese prime minister Tomiichi Murayama, 90, is still traveling around the country to elaborate his and the Social Democratic Party's brand of politics. And 83-year-old Yasushi Akashi, former under-secretary general of the United Nations, chairs the board of trustees of the International House of Japan.
A large number of Japanese people in the advanced age are spry and healthy and still active in society. Japanese women have enjoyed the longest life expectancy in the world for more than a quarter of a century, only the earthquake and tsunami in 2011 deprived them of the longevity crown that year.
The average life expectancy for a Japanese girl born in 2013 is 86.61 years, an increase of 0.2 years from 2012, according to Japan's Ministry of Health, Labor and Welfare. While the average life expectancy for a boy born last year is 80.21 years, a rise of 0.27 years on the previous year and the first time that it is more than 80 years.
Japan is home to both the world's oldest registered man and woman and half of the 40 known supercentenarians on the planet - those who have reached 110 years or more.
Japan is now one of the three "super-aged" countries - countries where more than 20 percent of the population are over 65, along with Germany and Italy. Moody's Investor Service reported recently that they will be accompanied by another 10 nations by 2020.
Japan's extraordinary longevity statistics have been attributed to the traditional diet of fish, rice and simmered vegetables, a comparatively high standard of living in old age, and easy access to healthcare. Japan's Health Ministry claims that Japanese people's extraordinary longevity is largely due to improvements in the diagnosis and treatment of cancer, cardiac disorders and strokes, Japan's three biggest killers.
Although not everything in Japan is conducive to a long life - the Japanese have a relatively high intake of salt due to the widespread use of soy sauce in the diet, alcohol consumption is also high, and the nation has a large army of smokers, compared with other developed countries, and people put in notoriously long hours, which is a source of stress - the lifestyle that Japan's older folks adopt helps keep senility at bay. When they retire from a busy lifetime of working too many hours, they don't settle into their easy chairs and watch TV. Instead, retirees in Japan stay active, and many of them continue working by choice and not economic necessity.