Given Japan's treatment of China in the first half of the 20th century it's no surprise that many Chinese hold very negative feelings about the land of the rising sun. At the same time, Beijing does go over the top, using educational texts, movies, and other means to highlight this past. The goal is to essentialize this earlier behavior as eternal Japanese character traits that disqualify Japan from the right to have a military, to be a leader in Asia, and have a permanent seat on the UN Security Council. With Japan sidelined and the view of many in China that the US is not genuinely a part of the region ("Asia-Pacific" is a US myth to many Chinese), it would leave China as the only legitimate leader for the region.
But China's approach toward Japan is not winning it any friends, and I expect this is entirely frustrating to Chinese. In the Fall of 2010, a Chinese fishing vessel collided with the Japanese Coast Guard, and the fishing boat's captain was detained for several days. In addition to permitting public protests, China responded by temporarily shutting off exports of rare earths to Japan. These metals are vital to a variety of Japanese industries, and the goal was to teach Japan a lesson by showing how dependent it is on China's good will. But to China's surprise, the US and other countries interpreted China's scheme as an indictor that China only followed international rules when convenient and could dismiss them whenever necessary. The US, EU, and Japan later sued China in the WTO over its broader policy of export restraints for rare earths and won the case this past summer. The effect on the rare earths sector was minimal -- demand had already fallen dramatically -- but a broader point was made.
It apparently fell on deaf ears because China is at it again. This time Beijing announced a new "air-defense identification zone" that intentionally includes the Diaoyu Islands/Senkakus, a large swath of Japan's own IDIZ, and even a small segment of South Korea's IDIZ. Chinese appear to believe that their strong negative views of Japan must be shared by others, and that no one would come to Japan's defense. Wrong again. The US immediately flew two B-52's over the airspace without prior notification to Beijing and in contradiction to Beijing's original pronouncements, the US faced no consequences. Other countries in the region have criticized China's effort as going too far and appear to welcome the US's display of disregard for China's assertion of new rights.
China's approach toward Japan is self-defeating. Taking an aggressive tact toward the East China Sea and Diaoyu Islands/Senkakus will not win Beijing any friends; in fact, it will push others into the waiting arms of the United States and Japan. It may also have the effect of reducing tensions between South Korea and Japan. (It is not even clear to me this is popular domestically given that it raises the prospect of conflict, and average Chinese aren't really interested in going to war over a small group of uninhabited islets.)
Despite previous history, and even the denial of that history by a tiny segment of the Japanese population, Chinese are going to need to figure out how to come to terms with this past and put it in the past, entirely. China's Japan complex could end up being a chain that keeps China from fulfilling the "China Dream" of becoming a well-off society and respected globally.