Although the first sequel to the game, Ryu ga Gotoku 2, has yet to be released outside of Japan, a third game in the series--known as Yakuza in the west--has been announced for Japan.
This latest issue of Famitsu, Japan's influential gaming magazine, has a seven-page feature on the new game, which appears to be set in Japan's Edo period--around 1605--as opposed to the modern-day setting of the first game. The official Web site for the series also has a countdown to the game's release on the front page.
The first Yakuza game for the PlayStation 2 was written by famous author Hase Seishu, and followed the adventures of a Yakuza called Kazuma Kiryu. Kazuma, framed for the killing of his clan boss, is released from a lengthy spell in prison to find that his best friend has disappeared, and he agrees to help a mysterious young girl who is searching for her mother. Yakuza--titled Ryu ga Gotoku in Japan--was released in the US and Europe in 2006. A sequel to the game, Ryu ga Gotoku 2, was released solely in Japan in December 2006, and there are no current plans to bring it overseas.
A Sega Europe representative confirmed the third game's existence and its Japanese release details, although he added, "There are currently no plans to release it in Europe." It is currently a PlayStation 3 exclusive and due in early 2008.