Kyuzo’s father Heihachi is one of the busiest sharpeners in Sakai. Heihachi’s workshop room and corridor were always filled with knives waiting to be sharpened. Although Kyuzo initially worked under his father to learn the foundation of rough sharpening, eventually he became a student of Kambei, known as one of the best sharpeners in Sakai because he knew best how to sharpen wide double bevel knives. After a few years of training, he built his style based on both his father and Kambei’s respective styles. Today, Kyuzo is one of only a few people who can sharpen wide double bevel with really good Shinogi-line in Sakai, one of the most challenging techniques in sharpening.
Message from Craftsman
Because Tanaka's way of quenching, knife does not produce a Kurouchi dark finish enough. So in order to produce the finish, which is both aesthetically pleasing and useful in protecting against rust, sharpener uses a special and secret technique that has been used in Sakai for a long time and etches the surface of the knife.
This way of finishing creates the dark and beautiful Kurouchi finish found on this special line. While both types of Kurouchi finishes can fade over time, the etching technique used by sharpener may fade faster.
This is not signed that anything is wrong with the blade. so please do not worry if this happens, as it is natural.