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.