I am a Chinese in Japan. After my graduation from Shanghai University, I came to Osaka University for a master degree.
Japan is actually better than what I thought. Nice people, clean environment, etc. However, before my coming to japan, I didn't like Japan so much. So, what causes the emotional disagreement between China and Japan?
From my viewpoint, it is ignorance. The ignorance leads to misunderstanding, and misunderstanding leads to hatred.
The two countries are near neighbours. A great part of both our cultures share the same origin. We even share many same characters in language. We think we know each other well, but in fact, not.
Modern Chinese don't know much about modern Japan. Most of us still think Japan as the aggressive old Japan of WWII. Most of the Chinese people don't know the modern democratic Japan.
On the other hand, Japanese don't understand why Chinese people dislike Japan so much. I have a very good Japanese friend. He has good personality and we share same interests. Once he asked me why Chinese people dislike Japan and I introduced the history and explained the reason to him. To my surprise, he was very much unaware of the history details and the severe criminals committed by Japanese army in WWII. He found it was hard to believe and asked me to give him some material to support my words. It took me some time in Library and Internet to find some relatively objective English materials. However as I know most Japanese people will not even bother to doubt the ambiguous textbook and search for some non-Japanese materials regarding history. The ignorance in history makes Japanese think that the dissatisfaction from Chinese people comes for no reason, or because of jealousy, uncivilization etc.
Every country has its own dirty history, but I don't understand why it's so hard for Japanese government to face it's past and admit it bravely rather than white washing it by publishing even more biased textbooks. I think Chinese people are not asking anything from japan except for a thorough commitment of wartime crime and a sincere apology.
I like Japanese people around me and I like Japanese culture in which I can find the trace of the ancient China virtue that has already been hard to see in modern China. But I really don't like the rightwing government of Japan, not because of its nationism but because that it is not brave enough to carry the history burden.