The nation's territorial disputes heated up in August when the South Korean president made an unprecedented visit to the Takeshima Islands, which his country holds, and Chinese activists briefly landed on the Japan-administered Senkaku Islands.
In July, Russian Prime Minister Dmitry Medevedev toured the Russian-held islands off Hokkaido to boast Moscow's control.
This month the central government is poised to purchase three of the Senkaku islets from a Saitama family, angering China further.