 Yūgen gaisha are based on the German GmbH and were implemented in Japan in the Limited Company Act (有限会社法) of 1940.The Companies Act of Japan, implemented on May 1, 2006, replaced the yūgen gaisha with a new form of company called gōdō gaisha, based upon the American limited liability company.Following the implementation, no new YKs were allowed in Japan, but pre-existing YKs were allowed to continue their operations as kabushiki gaisha under special rules.