I recentry watched 'The Rape of Europa' in Netflix, it talked about the industrial scale robbery and destroying of thousands of works of art in Europe by the Nazi on invaded countries.
Was there a similar attitude of the Japanese on the culture of the countries they invaded? Or how was art treated?
Provenance & repatriation are a huge area of interest for me, so while Asian art & history isn't my specialty, I did a bit of research because your question really intrigued me!
The consensus seems to be, quoting from a UPenn Law article on the subject, that "there is considerable evidence that certain cultural assets of Korea were adversely affected by the presence of Japan." Japanese government officials seized many Korean cultural objects and property, including books, statues, pottery, bronze and gold sculptures, and calligraphic works. Some of these objects remain in either private or public collections in Japan, others have been returned to Korea. In 2010, the Prime Minister of Japan promised to return objects stolen during the invasion back to Korea. This referred only to objects in public collections, however, not any held by private citizens.
The same is likely to have happened in China, although centuries of domestic looting in China makes it slightly harder to ascertain what was stolen when and by whom. After WWII was over, General MacArthur reported finding "great hoards of gold, silver, precious stones, foreign postage stamps, engraving plates and . . . currency not legal" in Japan, artefacts from both Korea and China.
Overall, it seems that while such theft definitely occured (even, as this article claims, on a larger scale than in Europe), it wasn't in as destructive a manner as the Nazi looting during WWII.
(If anyone else has more knowledge on the subject, please chime in and correct me!)