Interestingly, the sort of historical narrative you describe also appears within imperial/colonist nations. In Britain (or more properly the United Kingdom) this sort of historiograpical template is applied to Scottish and Welsh history and in the Scottish case has been brilliantly and decisively dismantled by the Marxist historian Neil Davidson. (I’m not even going to start on Ireland, which seems to be the granddaddy of all colonial/postcolonial narratives – a sort of testbed for everywhere else.) Then, even in more supposedly homogeneous and less historically contingent versions of the ‘nation’ such as (South) Korea and Japan, we find that these stories of colonial oppression and emancipation are replicated internally on a smaller scale (eg Cholla province in Korea, Okinawa/Hokkaido in Japan), which just goes to demonstrate the (I have a feeling I’m going to start over-using this word) fractal nature of empire/hegemony/power relations.

Returning to your final point, I think one of the many things that the slightly obsessive discourse on Japanese colonial legacies occludes in South Korea is the nature of the attempted/aborted modernisation process of the late nineteenth century, prior to colonial domination proper. Of course, one can argue that this process itself was hugely influenced by Japan, which it was, although there were other influences too. But there were, in my opinion, much bigger structural/historical factors at work here, which I think gave late developing capitalist countries from Germany onward a broadly similar character. It is certainly no accident that Japan and Choson turned to Germany for their model of the modern nation state and its associated paraphernalia. Basically, to put this in baldly Marxist terms, when other countries in the world have already become successful capitalist nations, new independent national centres of capital accumulation can only be successfully formed through mass coercion and mobilisation, hence the militarisation of society, statist direction of the economy and the penetration of the state into all areas of life (all things that characterised the Soviet Union too, when its forced industrialisation drive had really got underway in the early 1930s).