Ema

prayer board

Ema are prayer boards hung at Shinto shrines (and sometimes Buddhist temples). They are usually made of wood and have a wish or request to the kami (gods) written on them. Originally horses were presented to shrines when one had a special request, but horses were eventually replaced with clay figurines in the 8th century and are now replaced with ema (which literally means "picture of a horse").

Simple Guide to Shinto
Ian Reader