What is "dotaku"

are Japanese bells smelted from relatively thin bronze and richly decorated.

Dotaku were used for about 400 years, between the second century B.C. and the second century C.E. (corresponding to the end of the Yayoi era), and were nearly only used as decorations for rituals. They were richly decorated with patterns representing nature and animals, among which the dragonfly, praying mantis and spider are featured. Historians believe that dōtaku were used to pray for good harvests, as the animals featured are natural enemies of insect pests that attack paddy fields.

According to Japanese folklore, dōtaku were used as emergency bells (such as a watch tower’s bell); intended especially in cases of invasion, particularly invaders from the Korean peninsula. When sentinels spotted invaders, they loudly rang the dōtaku as an alarm, so that people could hide themselves or their possession, and to alert warriors to prepare themselves to repel the enemy.

There is a dotaku museum devoted to the bells in Yasu city, in Shiga prefecture, in central Japan.