Originally, Kogai hairpins were a practical item used to secure the topknot of a hairdo however, with the onset of more complex hairstyles in the late Edo period their usefulness diminished and, became much like an ornamental accessory.
本来は髷の根を固定する実用的な道具であったが、江戸後期の複雑な結髪になると用途は後退し、ほぼ装飾品と同じとなる。