Teru Teru Bozu (てるてる坊主? “shine shine monk”), is a craft made of white paper or cloth bound together with a bit of string. It looks like a little ghost that Japanese farmers hang outside their window and is believed to have magical powers to bring good weather and stop/prevent rain.
What looks like a simple custom is actually a prayer to ancient gods and to one of Japan’s monster clan, the yokai called Hiyoribo, who is said to come from the mountains of Hitachi-no-kuni, modern day Chiba prefecture and his season is the summertime. Hiyoribo is said to be a yokai who brings sunny weather, and who can not be seen on rainy days.