This is a youkai that will only appear during sunny days and not during rainy days. She lives in the deep woods nearby Ibaraki. One will be lucky if he or she sees Hiyoribou, and that day is guaranteed to be in sunny weather. People would craft a Hiyoribou-shaped doll and put it under the roof to wish for a sunny day. As time goes by, it then becomes Teru Teru Bozu - a toy for the children.
(Source: onmyoji-card.com)