There's a new billionaire in Japan: Yoshikazu  Tanaka, who also boasts the title of the youngest self-made billionaire  in Asia. Listed at No. 18 among Japan's 40 richest, Tanaka is worth $1.6  billion, almost double the $850 million he was listed at in 2009, due  to a pop in the stock price of his online social network, Gree. 
(Mark Zuuckerberg, facebook founder)
There's  a new billionaire in Japan: Yoshikazu Tanaka, who also boasts the title  of the youngest self-made billionaire in Asia. Listed at No. 18 among  Japan's 40 richest, Tanaka is worth $1.6 billion, almost double the $850  million he was listed at in 2009, due to a pop in the stock price of  his online social network, Gree.
After graduating from Nihon  University, Tanaka worked at Sony and then joined Rakuten, an online  shopping site run by Japan's sixth richest person, Hiroshi Mikitani.  While there, he started Gree for fun and after it started drawing fans  he struck out on his own. His site allows its now 15 million users  (almost double a year ago) to customize their game-playing avatars by  purchasing clothing and accessories.
Tanaka reminds us once again that even when the world is in  the throes of economic turmoil, young, innovative entrepreneurs can  strike it rich. He is one of a long line of tech tycoons from Michael  Dell to Bill Gates who made their initial fortunes in their twenties and  thirties. Today eight billionaires under the age of 40 have earned  their money in technology. That is up from just four in March when we  published our ranking of the World's Billionaires. At the time there  were only three other self-made billionaires under 40 whose money was  made in other sectors; eight more had inherited at least part of their  fortunes.
Of the current eight, four are from China, three are  from the U.S. and one is from Japan. Several became wealthy from online  games or social networks, and all are still involved in the companies  they founded.
For most, like Tanaka, their companies started out  as hobbies but yielded billions. The youngest, Mark Zuckerberg, became a  billionaire in 2008 at age 23, making him the youngest billionaire in  the world. As a Harvard sophomore Zuckerberg created Facebook for his  campus. The social networking site quickly spread to other schools and  now has 350 million members. College dropout Zuckerberg is worth $2  billion now.
These entrepreneurs are already huge successes but  they still have a long way to go to catch up to Bill Gates, the world's  richest man.
In 1987 Gates was officially declared a billionaire  in the pages of Forbes' 400 Richest People in America issue, just days  before his 32nd birthday. As the world's youngest self-made billionaire,  he was worth $1.25 billion, over $900 million more than he'd been worth  the year before, when he'd debuted on the list. Ironically, he was  quoted describing himself as a "stick-in-the-mud, over-30 guy now."
Gates  has been a billionaire ever since 1987, but not all young tech moguls  have had his endurance. Jerry Yang and David Filo, co-founders of Yahoo!  were 30 and 32, respectively, when they became billionaires in 1999.  They fell below the mark in 2001 and 2002, as their fortunes fell to  less than one-10th of the highest value in 2000. Both climbed back on in  2003 but aren't worth anywhere near their peak of more than $6 billion  in 2000.
Joe Liemandt, the founder of software company Trilogy,  was worth $1.5 billion when he was 32 in 2000. The following year he  didn't make the cut. In 2001 hundreds of Trilogy employees were fired  and Liemandt shook up its business model. He has yet to rejoin the  ranks.
Of today's young tech billionaires, only Sergey Brin and  Larry Page of Google stand much chance of overtaking Gates in terms of  wealth. Last March, they were tied for 26th richest person in the world,  with $12 billion each. This fall, Bill Gates was worth $50 billion,  while Brin and Page were each worth $15.3 billion. The duo's wealth  could continue to climb as Google continues to grow; the company  recently expanded into smart phones.
Even if these young techies  don't catch up to Gates, they're still the creators of companies that  have changed the way we socialize, play and browse. Chen Tianqiao, worth  $1.3 billion as chief executive and chairman of Chinese company Shanda  Interactive Entertainment Limited, told Forbes in May 2005: "As an  entrepreneur in China, I respect Bill Gates, but I want to be China's  Chen Tianqiao, not China's Bill Gates."
Source : http://news.id.msn.com/forbes/business/article.aspx?cp-documentid=3827593