The bronze arrowhead has been dated to the Warring States period of ancient Chinese history, 475 B.C. to 221 B.C., China's state-run Xinhua news agency reported Thursday.
Researchers said the Chinese artifact, a "double-winged bronze arrowhead," was unearthed at the Minamigata ruins located in the city center of Okayama.
The arrowhead, 1.4 inches long by a half inch wide, was found together with pottery fragments and pieces of stoneware dated to Japan's Iron Age Middle Yayoi period, about 300 B.C. to 100 B.C.
The double-winged shape of the arrowhead represents a distinctive manufacturing style from the era of ancient China, suggesting it was imported by an influential group with care from the continent to western Japan, archaeologists said.
"Considering that there is a considerable time gap between its original production in China and the actual usage in Japan, the thin bronze arrowhead must have been used as a ritual item or burial good rather than a weapon," Minoru Norioka, director of Okayama City's properties division, said.