The masterpiece we introduce this time is a bronze mirror made in the fourth century. Mirrors, with their power to reflect people’s images or light fires, were regarded as sacred objects in ancient times. Many mirrors imported to the Japanese islands from China became symbols of authority and were buried as funerary objects in the graves of the mighty. This particular mirror, too, was unearthed from a burial mound, but it was made on the Japanese archipelago based on Chinese mirrors. Measuring 44.5cm in diameter, it is large by East Asian standards and was very expertly cast. The patterns on the mirrors on which it was based represented the world of the gods as imagined by the Chinese, but the Japanese craftsmen did not understand the symbols and transformed them into original patterns. This piece sheds light on the history of cultural transmission in ancient East Asia.