The Japanese newspaper, Yomiuri Shinbun, has just reported (2/8/2021) that "counterfeit prints based on paintings by Japanese masters such as Ikuo Hirayama and Kaii Higashiyama have been circulating in Japan for about eight years... An art dealer in Osaka Prefecture confessed to the Contemporary Graphic Art Dealers Association of Japan (Nippansho) that he sold fake works. Ten works have been confirmed to have been counterfeited so far, but the owner of a studio in the Kansai region who produced the fakes at the request of the art dealer told the Yomiuri, “I printed about 20 copies each of about 40 works.” This indicates that there may be as many as 800 fake copies." article here