Japan has called on the Chinese government to take steps against a surge of artificial-intelligence videos on Chinese social media mocking Emperor Hirohito, the wartime monarch, warning that the clips risk further straining already fraught bilateral ties.There has been a sharp increase in video clips released on Chinese social media in the run-up to a military parade scheduled for September 3 to mark 80 years since Japan’s surrender ended World War II.In one video, the wartime emperor...