This is not so, and there are very good reasons why. Japan did not usually ‘invade their neighbours’. They didn’t do it under the Shogunate and they didn’t do it under Meiji.
Maybe not but they have been invaded by Japan several times in their history.
They even ruled long enough to build castles..
http://en.wikipedia.org/wiki/Japanese_castles_in_Korea
Hideyoshi in 1592 was one of them.
China had Korea in its fist a lot too, Korea had to pay tribute to China for centuries. I wasn’t trying to pick on Japan.