Japan's offer to return the royal Korean texts also represents progress that overturns Tokyo's previous position that all issues regarding the colonial rule were settled in a 1965 package compensation deal between the two countries, Yun said. Under that agreement, Seoul received hundreds of millions of dollars in grants and low-interest loans from Tokyo.
Japan's harsh colonial rule left deep scars on the hearts of Koreans. During that period Koreans were banned from using their own language at schools and forced to adopt Japanese names. Hundreds of thousands of Koreans were also mobilized as forced laborers and sex slaves.
South Korea and Japan are key trade partners and cooperate closely in efforts to get North Korea to give up its nuclear weapons program. But issues related to the colonial rule have often badly strained their relations, with tensions flaring up whenever Japan attempted to gloss over its wartime past or lay claims to South Korea's easternmost islets of Dokdo in school textbooks or government documents.