The core steel is made from rare and hard-to-find domestic iron sand, and Yasugi steel, made by tatara iron making, is hand-hammered between the base metal and forged into kitchen knives. There are only about 50 craftsmen in Japan who can make forged kitchen knives. The knives made by Tottori Knife Forge in Chizu-cho, Tottori Prefecture, boast a sharpness rarely seen in other kitchen knives. The wave pattern on the surface of the blade represents the rough waves of the Sea of Japan.