It is believed Nazi Germany looted more than 500,000 artworks from other European countries during the war, according to the ministry. Poland has been looking for the stolen works and seeking their return. This is the first instance where artwork the Nazis plundered from Poland during the war has been found in Japan, the ministry said. The ministry discovered the painting was sold at an auction in New York in the late 1990s, but it still doesn't know how it came to Japan. Paweł Milewski, the Polish ambassador in Japan, has described the return of the painting as the symbol of friendship between Japan and Poland that has lasted more than 100 years.