I've recently been looking into Korea-Japan relations in order to understand the sorry state of affairs that exists between the countries today. A Korean person I was speaking to recently made an off hand remark about Japan being predatory and looting precious cultural artifacts from Korea during the Sengoku period, or thereabouts.
I have some concerns that 19th/20th century events have pushed some Korean media/scholars to inflate historical tensions as part of a nationalist narrative, and would like to know more about this aspect.
From the sengoku period until the beginning of the Meiji period, could Japanese treatment of Korea be characterized as exploitative and predatory? To what extent were significant Korean cultural articles such as books, temples, treasures, looted or stolen by the Japanese? Was this state organized, local lords, or piracy? Was this a major concern of Koreans during that era or only focused on retroactively?
The two main things responsible for the Korean view of Japan as predatory and exploitative are:
The Imjin War - Hideyoshi's invasion of Korea, 1592-1598.
Japanese colonial rule of Korea. Following more than a decade of Japanese pressure and interference in Korean domestic affairs, Korea was force to become a protectorate of Japan in 1905. This was followed by annexation in 1910, and colonial rule until Japan's defeat in WW2.
To this, we could add "Japanese" piracy, especially from the 14th to the 16th centuries. It should be noted that the pirates were not exclusively Japanese, and towards the end of this time only a minority were Japanese. Compared to the Imjin War and the colonial period, this piracy was only a minor issue.
The Imjin war was very destructive. Hideyoshi, following his unification of Japan, planned to invade China. He demanded passage through Korea for his armies, and assistance. The Koreans refused, and the Japanese invaded. There were two main rounds of fighting: 1592-1593 and 1597-1598. When the initial fighting ground to a halt with the Japanese having failed to conquer Korea, and the Koreans and Chinese having failed to drive the Japanese out, things settled down to peace talks, with lower intensity fighting continuing. Dissatisfied with the progress of the peace talks, the Japanese made another major effort to win in 1597, followed by a renewed Korean/Chinese effort to drive out the Japanese. The Korean/Chinese counteroffensive weakened the Japanese position, and with major Korean naval victories, it was difficult for the Japanese to supply their armies in Korea. This, and Hideyoshi's death in 1598, resulted in Japanese withdrawal (and a Japanese version of the withdrawal along the lines of "it was all Hideyoshi's idea, and when he died, we left - we weren't defeated at all").
The Korean economy suffered badly. Korean agriculture was damaged, Korean cities were fought over, burned, and looted. Hundreds of thousands of Koreans - mostly civilians - were killed. Many tens of thousands of Koreans were taken as prisoners to Japan, including skilled artisans - some were kept in Japan, and many were sold elsewhere as slaves.
While the Imjin War figures strongly in Korean memory as a basis for anti-Japanese feeling, the most important cause is Japanese colonial rule. Japanese rule brought some benefits, but was exploitative and oppressive. While Japanese rule resulted in modernisation and industrialisation of Korea, this was intended for Japanese benefit (also, it should be noted that Korea had already begun modernising before the Japanese takeover). Korean farmers were impoverished, land was taken over by Japanese landlords. The Japanese introduced a free public education system, but this was intended to produce loyal citizens of the Japanese empire. In the 1930s, the teaching of Korean language was banned, and the schools became a vehicle for replacing the Korean language with Japanese. Over 5 million Koreans were conscripted by the Japanese during WW2, for labour in Korea, Japan, and Manchuria (Manchuria was also a Japanese colony), and for military labour in Japan and outside (Korean labourers worked in New Guinea during the war), including women as conscripted military prostitutes ("comfort women"). Approximately 10% of the Korean conscripted workers in Japan died, and death rates in Manchuria were higher. From the Korean viewpoint (and many non-Koreans thoroughly agree), Japanese apologies and compensation after the war do not go close to making up for this.
As for precious cultural artifacts, the Korean government claims that many tens of thousands were taken to Japan during the colonial period. Over 1000 were returned by the Japanese after WW2, and many Koreans consider this thoroughly inadequate.
The recent memory of the colonial period is largely responsible for the Imjin War (and Japanese piracy) being held up as example of earlier Japanese attack on Korea and exploitation/looting/destruction etc. Without the colonial experience, the Imjin War would be rather distant. With the colonial experience, Japanese looting of cultural artifacts, enslavement of Koreans, and exploitation of the parts of Korea they controlled is seen as an early version of the colonial period. Modern history has made the Imjin War culturally relevant today for attitudes to Japan in Korea.