Hand-painted picture streamers have been passed down in Iwaki City, Fukushima Prefecture, since the Edo period. It is said that the flags were originally raised by samurai families during the May Festival to celebrate the birth of boys, and gradually spread to townspeople and farmhouses. Many of the designs feature heroes from the Warring States period, famous historical scenes, or Shoki, a god of academics who also wards off evil spirits from children. The designs are painted on cotton fabric by dissolving pigments in gojiru, a liquid made by grinding soybeans with water. The vivid colors resist fading.