Sakai Takayuki Tuna Maguro Bocho
The Tuna-Kiri or Maguro Bocho by Sakai Takayuki is made to put soft kitchen knife iron on Yasuki's traditional Nihonko or Hagane- which has been widely used for a very long time in Japan. The material makes extreme sharpness, very good edge holding and high working hardness.
You can grind it to extreme sharpness, which it retains for a long time.