OSAKA, JAPAN—Chinese news agency Xinhua reported the discovery of a bronze arrowhead dating back to between 475 and 221 B.C. in western Japan. The arrowhead was of the so-called "double-winged" style that is a distinctive sign it was originally made in China and imported to Japan. Archaeologists believe the arrowhead, which measures fewer than one-and-a-half inches long, was used for ritual purposes, rather than for military ones.