Anybody visiting a japanese shrine must have seen the characteristic Ema boards or wishing plaques, covered in writting or artwork. Originally a Shinto custom, and therefore common in shrines, but they can also be found in Buddhist temples.
Ema actually means horse picture. Horses were considered the vehicle of gods and therefore horses were often donated to shrines of wealthy worshipers. As not all could afford to donate a horse in hope that the deity would listen to their wishes, poorer worshipers began to donate horse figures and drawings. Over time this evolved and all sorts of artwork we donated – Yanmei below at the Fushimi Inari shrine outside Kyoto.
Modern day Ema boards take all shapes and forms. You can find heart shapes, flower, shapes, even character shapes! (Hello Kitty, Disney, and Rilakkuma to name but a few), as well as a plethora of designs on traditional 5-sided boards, often with folded objects (good luck charms).
One can normally purchase an Ema board from the office at the shrine. They usually come with artwork on one side, and a place to write your wish and name and address on the otherside. But it is up to you as the wisher, and I have seen wishes written across the artwork. Once you have made your wish, you can hang up the Ema board. All shrines have a special area dedicated to the Ema. This is usually either a board with hooks, or even an entire wall, depending on the shrine.
If you ever wondered what happens to all the Ema boards? They usually sit in place until Hatsumode (the first visit following New Year), after which they are ritualistically burned. When the Ema are burned in the sacred fire, prayers are said to help fulfil the wishes – to symbolically liberate the spirit of the wish into the world.