Newly declassified diplomatic documents show that South Korea had a plan, ahead of its president's visit to Japan in 1990, to seek a stronger apology from the then Emperor of Japan.
The documents declassified by South Korea's foreign ministry on Monday contain records from April of 1990, ahead of then President Roh Tae-woo's trip to Japan.
The records touch on the remarks by Emperor Showa -- the father of then Emperor Akihito -- made in 1984, when then South Korean President Chun Doo-hwan was in Japan.
Emperor Showa said it's extremely regrettable that the two countries had an unfortunate past and that it should never be repeated.
The documents describe those remarks as vague, and point out that the ambiguity led to discontent among the people of South Korea.
The documents say that while President Roh was in Japan, the Emperor should clarify what the "unfortunate past" actually was and make clear his remorse.
The documents also reveal South Korea's intention to invite then Emperor Akihito to the country as his first foreign destination after his accession to the throne, if Seoul found apologies from the Emperor satisfactory during President Roh's visit.
In the next month, May of 1990, during a banquet for President Roh, the Emperor said he thinks of the sufferings South Koreans went through during the unfortunate period, which were caused by Japan, and cannot help but feel the deepest regret.
While in Japan, Roh invited the Emperor to visit South Korea. But the visit was not realized, as relations were strained over historical issues and other matters.