This plane (Kanna) is made by third generation plane maker Master Tsunesaburo.
The core blade is Blue Paper Steel and the hardness is HRC64-65. The other side of the blade is made of wrought iron which was produced in England before 1889. In those days, fuels used for refinement are wood, charcoal, etc., and they are not powerful enough to get the temperature to melting point and the dissolution was not complete. As a result, particles are rough and weak. Further, some impurities and oxygen stoma are included. Iron having these characters are very easy to sharpen and are ideal for the soft part of plane blade. This is one of the more popular planes, good performance, easy to use and cost effective.