On the face of it, the current controversy over Japanese history textbooks is just one more example of Japan not facing up to its militaristic past. On a deeper level, however, Korea's decision to forgo further liberalization of Japanese cultural imports until the offending texts are revised underscores the unique emotional relationship that exists between the two countries.
Up until only a few years ago, the Republic of Korea banned Japanese movies, music, TV programs and other entertainment-related products as a way of punishing Japan for its annexation of the Korean Peninsula during the earlier part of the century. Japan has had no reciprocal ban on Korean products for obvious reasons, and in any case there is a sizable ethnic Korean population in Japan that bought such products even if the Japanese themselves didn't.
So while a newer generation of South Koreans has grown up understanding the terrible things that Japan did to their country before they were born, Japanese youths are fairly clueless about the relationship in general, not so much because of biased textbooks, but because Japanese history classes rarely cover the 20th century.