The San line perfectly combines elegance with utility. 3 Layer (sanmai) construction, with VG5 core heat treated to a perfect hardness of HRC 61, giving the knife a very strong edge retention. The bevel is hand sharpened and polished by hand, giving the edge an unmatched sharpness.
The outer layers are comprised of soft stainless steel that was given a beautiful hammered matte finish. Combined with a stabilized wood handle, integrated bolster, the Tamahagane San is a prefect addition to the kitchen. 

Kataoka Hamano is a professional kitchen knife maker based in Tsubame, Niigata, Japan. Tsubame is a centre famous for steel products, a lot of high-end stainless cookware is from there. While the city of “Tsubame” may not sound familiar, it is actually adjacent to another famous (handmade) knife centre: Sanjo, in fact they share the same bullet train station, which is conveniently named as “Tsubame-Sanjo Station”
You are probably quite familiar with Seki, a major kitchen knife making city with a lot of mass-product knife brands like Shun, Yaxell, Misono, Masahiro (even Henckels Zwilling has a factory there). Tsubame is quite similar to Seki in this regard as it has a few mass-produced knife makers, notably Global. 
Kataoka Hamono use to do a lot of OEM jobs for other top tier brands in Japan, including the likes of Sakai Takayuki and Sakai Jikko. In recent years they have shifted their focus to build their own brands. Their industry focused brand Berito is very popular among Japanese chefs. For the consumer market, they market under the brand “Tamahagane”, with the meaning of great sharpness and pure performance. I really like the Tamahagane knives because some of their features and designs are just quite unique compared to a lot of the consumer grade knives that are already out there (and look identical):

Blade length:172 mm
Overall length:305 mm
Thickness at spine: 1.8 mm
Handle material: Stabilized Birch 
Hand wash and wipe dry, NO DISHWASHER
Please use the knife as it should be, not frozed food, and not as screw driver
Hand sharpen with waterstone, honing rod is not suitable for Japanese knives