It is said that Sakai city(Osaka) started to introduce iron forging techniques in the 5th century when a lot of iron were required to make ancient burial mounds.
This technique was inherited as the sword forging technology after the 12th century when Samurai period started, and many swords were made in this region.

During MUROMACHI period(1333 A.D.~), many tobacco cutting knives were produced in SAKAI city to meet the demand from tobacco producers and smokers. Tobacco leaves were imported to Japan from trades with western countries during the same period.
Japan introduced gun-making techniques from Portuguese in 1543 A.D., and Sakai was the center of the production.

Furthermore, The quality of gun and tobacco cutting knives there was quite impressive to the men of power such as Nobunaga Oda, who gave the city extra-special treatment.

Their exceptionally high-quality products were accredited during Edo period by TOKUGAWA government. For the government to distinguish their products from others, it put the unique stamp called Gokuin (極印「堺極」)on their selling products so that it was able to have a monopoly. In this way, their products became famous and popular nationwide.

During EDO period, several iron-forging makers in Sakai invented various kinds of cooking knives, such as DEBA(出刃), which we even use now. It is said that 90 % cooking knives used by professional chef come from SAKAI(堺).

Sakai Cooker Knife