c1815 Regency era Hair pin. Hair pin, seed pearls mounted on mother-of-pearl. These long, tong, U shaped pins were functional as well as decorative. These would have been used in conjunction with plain pins for added support to the "updo" styles of the day. These are thicker and longer than the hair pins and bobby pins normally found today. See what the back looks like at http://collections.vam.ac.uk/item/O115271/hair-pin-unknown/
The oiran were considered a type of yūjo (遊女?) "woman of pleasure".However, they are distinguished from ordinary yūjo in that they were entertainers, and many became celebrities outside the pleasure districts. Their art and fashions often set trends and, because of this, cultural aspects of oiran traditions continue to be preserved to this day.