I'm interested in postcolonial histories of Taiwan and Korea, and the question that Diana posed a while ago is a big theme to me, too. I put some speculations as a comment to her entry, but I think this article on Taiwan's history shows how differently they regard the memory of the Japanese occupation to serve the goals of their nationalist histories: Describing Taiwan's real history.
Since the goal is to separate Taiwan's history from China, the article emphasizes that Taiwan was occasionally ruled by foreign powers, of which China is just one; "Japan occupied" is an incorrect expression that might give an impression that Taiwan always belonged to China. (e.g. "Taiwan has never been a part of China except for 1945 to 1949 during the Chinese Civil War when the Chinese colonial regime occupied Taiwan and slaughtered many Taiwanese... The new textbooks correctly say that during the Japanese colonial period Taiwan was "Japan-governed" rather than "Japan-occupied.'") The new textbooks apparently play down the Rape of Nanjing, too (Taiwan textbooks downplay Japan massacre)