Also called *kurinuki kaerumata 刳抜蟇股. A frog-leg strut that is scooped or gouged out. By the second half of the Heian period, frog-leg struts were gradually becoming more ornamental and less structural than the original solid board frog-leg struts *kaerumata 蟇股. Hence, an openwork type of frog-leg strut was created. The earliest struts were not really carved out of a solid panel but were carved in two pieces, one the reverse of the other. They were joined together to look like a single carving of genuine frog's legs or honkaerumata 本蟇股.
During the Kamakura period, they were carved in one piece. A variety of designs abound, but during the proto-modern period (16th-19th century), they became ornate and the delicacy of the early openwork-style of frog-leg struts was lost.
Ujigami Jinja Honden 宇治上神社本殿 (Kyoto)