Japan and South Korea released a full-scale report on their joint history research Friday, detailing huge gaps in perception on key events that have repeatedly caused friction between the two nations.

Instead of a joint perception of history, the 1,900-page report merely presents the views of both sides, including Japan's 1910-1945 colonial rule, because it was "impossible" to map out a collective view, members of the joint group said.

The report is part of a bilateral project aimed at promoting mutual understanding and bridging gaps in perceptions of history. The project was agreed on in October 2001 at a summit between Prime Minister Junichiro Koizumi and then South Korean President Kim Dae Jung.