oscar and 可愛的兔兒, are both of you in form 3? It is because you will learn the 九一八事變 during the second term in form 3. The 九一八事變 was like this:
The Japanese army blew off a section of the South-Manchuria Railway and announced that it was the Chinese who had done it. She used it as an excuse to annex the northern part of China.
So, we must always beware of the militarism of Japan.