In December 2004,[2] Tanaka established Gree, Inc. in order to cope the growing number of users.
In February 2009, Tanaka was ranked 24th among "Japan's 40 Richest Billionaires" by Forbes Asia.
[2] In June 2010, 5 years after the foundation, Gree was listed on the first section of the Tokyo Stock Exchange.
[2] Tanaka was 33 years and 3 month at that time and the youngest founder whose company is listed on the TSE first section.
Tanaka was able to set his social network apart from the well established Japanese brands Mixi and DeNA by concentrating on mobile games and making partnerships with major Internet Service Providers.