Zakuri is a collective of blacksmiths in the Tosa region of Japan. Blue #1 is an excellent carbon steel for knives but it's reactive and you need to wipe it dry after using it. The high carbon gives the blades excellent sharpness and edge retention. You can sharpen these knives steep and they will hold their edges well. Each one is made by hand so they can vary a little in dimensions. These are excellent work horse knives with nice rosewood D shaped handles.
There is a small business card with a note in each box that reads: "I made them with my responsibility. I have inherited traditions and techniques of Tosa Uchi-hamono." - Zakuri Blacksmith Michikuni Tokaji