Faced with the aging and shrinking domestic population, Japanese companies and the government are joining hands to explore new business opportunities targeting low-income earners, not only in neighboring Asian countries but also in Africa.

Having gotten off to a late start in this field, they are trying to catch up with their European and U.S. peers, but they face difficulties in securing enough Japanese staff with the necessary language skills.

The "bottom of the pyramid" — some 4 billion people who earn less than $3,000 a year — make up about 70 percent of the world population. While their purchasing power per capita is low, collectively the market is worth about $5 trillion and rivals Japan's nominal gross domestic product.