The Japanese Mortality Database has been created as part of the research project "Demographic research on the causes and the socio-economic consequence of longetivity extension in Japan" (for the period 2011-2013), "Demographic research on longevity extension, population aging, and their effects on the social security and socio-economic structures in Japan" (2014-2016), "Comprehensive research from a demographic viewpoint on the longevity revolution" (2017-2019), and "Modeling and Comprehensive Analysis of Population, Economy and Society of Ultra-Longevity" (2020-) run by the National Institute of Population and Social Security Research.

Life expectancy in our country experienced a considerable increase in the second half of the 20th century. Internationally, Japan currently boasts a top class standard, being the leading country in terms of life expectancy. Additionally, according to the "Population Projections for Japan (2017 based)," life expectancy in 2065 is projected to reach 84.95 years for men, and 91.35 for women (medium variant mortality). As we move towards the future, Japan is expected to continue as the front runner in the race for longevity.

For us to be able to grasp an accurate understanding of the mechanisms and circumstances behind this unprecedented increase in longevity, as well as understanding how these affect Japanese society, we need to create a mortality database that can be used for performing a focused demographic analysis. It is essential to follow an interdisciplinary approach, by performing analysis from the points of view of society, economics, medicine, and biology. Furthermore, it is also necessary to do an analysis with regard to health, an aspect that impacts greatly on life span, and which is also a major element in determining quality of life. However, the current reality is that so far, there has not been a great deal of research done to obtain any comprehensive knowledge on the cause and impact of longevity based on core demographic analysis, and in cooperation with other related fields.

It is for this reason that these research projects have implemented a comprehensive reorganization, thus creating the "Japanese Mortality Database (hereafter known as JMD)," with the objective of performing a population analysis on our country's mortality table. These researches are based on an interdisciplinary approach, performing a comprehensive analysis of longevity, including health, from a variety of angles. It also takes into consideration how longevity affects society and the economy. In this way, JMD represents one element at the core of these research projects.