And Japan's richest person is....

A radical economic policy by Japan's Prime Minister Shinzo Abe not only helped trigger stellar gains in Japanese stocks last year, it also boosted the fortunes of the country's 50 wealthiest individuals, as ranked by Forbes.

In its Japan rich list published Thursday, Forbes said Masayoshi Son, the man behind Japan's leading internet venture Softbank, is the country's wealthiest individual with a net worth of $19 billion. That's up from $9.1 billion previously.

Last year, the 56-year old came in third place, but has since seen the biggest gains in both percentage and dollar terms thanks to a buying spree by Softbank. After picking up stakes in Finland's Supercell and U.S. phone distributor Brightstar, Softbank bought a 70 percent stake in U.S. -based Sprint Nextel last year.

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Masayoshi Son, chairman and chief executive officer of SoftBank.
Junko Kimura | Bloomberg | Getty Images

The company's shares have surged 90 percent in the past year to trade around 8,144 yen ($78).

Japan's economy has seen a rebound in the past year thanks to aggressive monetary stimulus from the Bank of Japan, which has helped the weaken more than 11 percent in the past year against the dollar and helped the rally 26 percent.

Noticeably, the Forbes Japan list is entirely comprised of males. Last year, Prime Minister Abe pledged to significantly improve female participation in the labor force by 2020 as part of his economic reform plan.

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Unlike the Forbes billionaire rankings, Japan's 50 rich list includes family fortunes. While an individual's personal stake must meet the $500 million entry requirement, which was raised from $400 million last year, Forbes takes into consideration a family's stake in a company.

Retailers, bracing for the impact of a rise in Japan's sales tax that kicked in on Tuesday, dominated the top ranks of the rich list. Out of the top ten wealthiest individuals in the world's number three economy, four amassed their fortunes through retail.

65-year old Tadashi Yanai, founder and CEO of Fast Retailing, one of Asia's largest apparel heavyweights, dropped to second place after coming in first last year. Still, Yanai's net worth rose to $17.8 billion from $15.5 billion in 2013.

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Tadashi Yanai, chairman, president and chief executive officer of Fast Retailing Co.
Jerome Favre | Bloomberg | Getty Images

The bulk of Fast Retailing's profits stem from its Uniqlo outlets which has enjoyed steady growth in same-store sales.

Hiroshi Mikitani, chairman and CEO of the country's biggest e-commerce firm Rakuten, retains his number 4 spot with a net worth of $7.7 billion, up from $6.4 billion in 2013.

Mikitani has expanded Rakuten's reach through a number of acquisitions, including America's Buy.com, a $100 million stake in photo website Pinterest and most recently, a $900 million acquisition of smartphone application Viber.

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Coming in eighth place on the rich list is Masatoshi Ito, honorary chair of convenience store giant Seven & I, which operates the popular 7-Eleven chain. Ito's wealth stands at $3.35 billion and is expected to grow as the retailer plans to double 7-Eleven units in the U.S.

In the tenth spot is the founder of discount shoe retailer ABC-Mart, Masahiro Miki with a $2.8 billion fortune. An amateur former boxer, Miki bought Nasdaq-listed LaCrosse Footwear in 2012 in an effort to expand globally.

The youngest person to make the list was newcomer 36-year old Naruatsu Baba, ranked number 15 on Forbes' list. Shares of his smartphone-game maker Colopl, have sky rocketed 750 percent since its 2012 market debut, making him $1.9 billion.