The Japanese university model of education is in reality more like a European model in which most of the work is focused on seminars and final projects, and where most lectures and other courses are borderline optional. However, due to post-WW2 reforms the Japanese university system is institutionally based on the American model, and therefore has a superficial structure of grades, credits, homework, etc. that is often but weakly related to the more important areas. This disconnect makes Japanese universities (which do have serious problems) look even worse than they really are, and in fact contributes to their degradation.
As a hypothesis I haven’t thought about this too hard or looked for any evidence but would like to see some discussion. Thoughts?