According to Forbes magazine's 2015 list of the wealthiest individuals in Japan, there were 34 Japanese-born billionaires in the world, not all of whom resided in Japan. The ten wealthiest Japanese residents had net worths ranging between $3.8 billion (Akira Mori, Masatoshi Ito) and $21.1 billion (Tadashi Yanai).
1. Tadashi Yanai: $21.1 Billion
One of the wealthiest self-made men in the world, Tadashi Yanai is a retail tycoon who saw a 65% increase in international sales for his Uniqlo brand between 2014 and 2015. The 66-year-old started out selling kitchenware in the 1970s, before opening his first standalone store in Hiroshima in 1984.
Yanai saw a near $3 billion bump in his year-over-year net worth from 2014, reclaiming the top spot from Masayoshi Son.
2. Masayoshi Son: $13.9 Billion
Masayoshi Son saw a $5.8 billion decline in his net worth from the 2014 Forbes rankings. Son, 58, the chairman and CEO of SoftBank Corp., has much of his wealth tied up in shares of his company. Since SoftBank is a major owner of Alibaba Group Holding Ltd., Son's place on this list is also tied to the performance of China's biggest e-commerce company.
3. Nobutada Saji (and family): $10.9 Billion
Nobutada Saji gave away the reigns of Suntory Holdings, the food and beverage conglomerate, in 2014. This was a historic event, considering that it meant a non-Torii family outsider would head the company; the Torii family has controlled Suntory Holdings since 1899.
Even after abdicating most of his business responsibilities, the 69-year-old Saji will continue on the company board of directors.
4. Hiroshi Mikitani: $10.5 Billion
At just 50, Hiroshi Mikitani is as active a billionaire as you can find. He is chairman and CEO of Japan's largest online retailer, Rakuten, and he also owns Ebates, a U.S.-based rebate website. He bought OverDrive, an American e-book store, for $400 million in 2014, just before spending $300 million to buy a 12% ownership stake in the private car service Lyft.
Mikitani is also highly involved in Japanese politics, even advising the prime minister on technological and economic matters. Mikitani is also a Harvard-educated former exchange student with a second home in California, and he has plans to make Rakuten an English-speaking company despite being based in Japan.
5. Takemitsu Takizaki: $8.8 Billion
The founder of global electronic components company Keyence, Takemitsu Takizaki saw his net worth jump by nearly $2 billion between 2014 and 2015. His company is best known for holding a small army of technological patents and pouring huge sums of money into research and development (R&D).
6. Keiichiro Takahara: $5.4 Billion
Keiichiro Takahara, 84, is the long-retired founder of Unicharm, which makes diapers, napkins and other personal items. The company is still in the family, run by his son Takahisa, and is thriving on a booming Chinese market.
Unicharm sells more adult diapers than baby diapers in Japan, likely because of the country's aging population.
7. Han Chang-Woo: $4.9 Billion
Han Chang-Woo is actually a native Korean; he spent the first 14 years of his life there before illegally immigrating to Japan after the end of World War II. He earned a degree in economics from Hosei University seven years later. In 1972, he founded the Maruhan Corporation, which runs recreation and entertainment establishments.
Han, 84, did not become a naturalized Japanese citizen until 2002, long after he became a famous Japanese-Korean businessman.
8. Kunio Busujima: $4.4 Billion
In Japan, pachinko acts as an arcade gaming or gambling system, similar to what you'd find in American casinos. Kunio Busujima saw the potential in pachinko machines in the mid-1960s. Today, his Sankyo company is the second-largest manufacturer of pachinko machines in the world, and his son Hideyuki runs the company.