棹 Sao / Pole

What is Sao in Japanese Katana terminology?

This refers to the thinner part on the opposite side of the ear pick of the Kougai (hairpin). This side is used when arranging the hair. The Sao is designed to be thin and pointed to easily slide through the hair and help in arranging it. It is an essential part of the Kougai, which is a traditional Japanese grooming tool.