During the Imjin Patriotic War (1592-1598) the Japanese invaders not only destroyed the valuable Korean cultural assets at random but also plundered many of them and even were impudent enough to make them their own national assets.
They even organized a special unit only in charge of the plunder of the cultural assets apart from the combat forces to seize in everywhere the Korean wealth such as various books, metal types, paintings, bells and so on and even robbed civilians of their daily goods.
The majority of their plunder was the books which recorded the historical development of Korea.
Toyotomi Hideyoshi, chieftain of the invasion, drove the military bosses to the plunder of the Korean cultural assets and his kotowing henchmen looted a great deal of books to flatter to their chieftain.
Ukida Hideie, one of the bosses of the invader army, asked Hideyoshi in an interview on the eve of his departure to Korea what would be a good souvenir for his chief physician.
At the time, Hideyoshi told Hideie to present him medical book since he was a physician.
It is said that Hideie presented him many medical books looted from Korea.
Hideyoshi appointed many monks from temples to his archive secretary cum staff officers to plunder many types and books in Korea.