Naniwa tortoiseshell, Osaka betkko works
Among the tribute that Ono-no Imoko, an official envoy to the Sui court, brought back to Japan from Sui in 608 was an art object in which tortoiseshell was used. In Shosoin (the Imperial storehouse), there are also some tortoiseshell products brought into Japan in the same period. The technique of tortoiseshell work was introduced from China in the early Edo-era. Later in the Genroku-era, tortoiseshell began to be used to make accessories for high-ranked yujo (the prostitutes) and wives of daimyo (domain lords). With the flourish of Edo chonin bunka (culture of townspeople), a lot of tortoiseshell was used for personal items such as kanzashi (hair ornaments) or combs. Since then more complex techniques of carving, makie (gold and silver powder), and zogan (damascene) were developed. Tortoiseshell materials are made from the shell of the hawksbill turtle, the shell of which is up to 1m long. The shell is pressed flat and cut out into panels of appropriate sizes, then the panels are pasted together. At the present, Tokyo, Osaka, and Nagasaki are the three largest centers for tortoiseshell work. Osaka is known for fine carving techniques such as openwork and its main products are brooches and other accessories.