Who would win in a hot war between Japan and China? The more limited the scope of the engagement, the better the chance for Japan to prevail. While China has more ships and planes, Japan has better ships and planes, with more maneuvering experience.
The latest aggressive Chinese move in the Western Pacific? Decreeing that all fishing vessels must have Chinese permission to operate in the South China Sea, virtually all of which it claims as its sovereign territory to the dismay of the other nations on the South China Sea.